BSPPFit NEWS --- significant changes between releases

Version 0.145.0 (2026-10-11)
============================

* The standalone util.scad is removed: the helpers it held were already carried inside bsppfit.scad (since 0.103.0), and the standalone copy had fallen behind. A project that included util.scad directly should include bsppfit.scad instead, which provides the same helpers and more.

Version 0.144.0 (2026-10-11)
============================

* The models' male-thread clearance parameter is now BOSL2's own "undersize" (the amount to decrease the thread diameters, in mm), replacing "male_slop"; the global default is BSPPFIT_UNDERSIZE. The old value was radial, so undersize = 2 * male_slop (the bench value 0.05 for a PETG male in a brass G1/2 female becomes 0.10). A model that still passes male_slop gets OpenSCAD's unknown-argument warning and no allowance. It applies to male threads only. BSPPFit now calls BOSL2's bspp_threaded_rod() directly and the diverted copy is retired; BOSL2 2.0.767 or newer is required, and bsppfit.scad refuses to load on an older one. An elbow with a female port no longer has its female threads shrunk by a non-zero value.

Version 0.143.0 (2026-09-21)
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* The ten dedicated per-fitting model files (Nipple.scad, Pipe.scad, Elbow.scad, Reducer.scad, Cap.scad, Plug.scad, Union.scad, HexBush.scad, HoseTail.scad, Manifold.scad) are retired. They were kept only as the equivalence-test oracle for the mono-file bsppfit.scad's wrappers; with a real OpenSCAD build available for the first time since the source tree was flattened, all ten topologies were confirmed equivalent, and bsppfit.scad is now the library's sole implementation. The render pipeline and documentation are updated throughout to match.

Version 0.142.0 (2026-09-21)
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* bsppfit-api.html's Index link now honours ./configure INDEX=..., matching every other document; it previously ignored the configured value entirely, since api2doc (a plain script, not an Org export) never went through the substitution path the rest of the documentation set uses. FutureResearch.org's oracle-file-retirement decision is now its own tracked item rather than buried inside an unrelated one; a large-scale review removed a substantial amount of content that was already complete or already duplicated in ResearchJournal.org but had never been cleaned up.

Version 0.141.0 (2026-09-05)
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* model-docs and model-doc-check's openscad-docsgen failure diagnostic now names the exact reason a plain "command -v openscad-docsgen" run outside these scripts can disagree with them: both scripts prepend the user's .local/bin directory to their own PATH if not already present (pip/pipx's usual install location), already documented in each man page's PATH entry and now cross-referenced directly from the diagnostic itself.

Version 0.140.0 (2026-09-05)
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* model-docs and model-doc-check's openscad-docsgen self-test diagnostic now prints the executable's own path and shebang line directly, rather than asking the user to re-run a command in a separate shell whose PATH might not match and give a misleading answer.

Version 0.139.0 (2026-09-05)
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* model-docs and model-doc-check now self-test openscad-docsgen before attempting a full run, catching the case where the console-script wrapper exists but its own interpreter has lost access to its module (a common symptom after a Python version change) with a specific, actionable diagnosis instead of a bare traceback. The diagnosis and its fix commands cover both pip- and pipx-managed installs.

Version 0.138.0 (2026-09-05)
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* Fixed the API-documentation build, silently broken since the 0.136.0 flatten: model-docs, api2doc, model-doc-check, equivalence-test and checkxref each assumed they lived one directory below the project root and now correctly find their files at the root itself. Audited and corrected the same class of staleness throughout all nine command-line tools' man pages.

Version 0.137.0 (2026-09-04)
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* Fixed roughly fifty broken illustration links in Taxonomy.org and broken links on the project's own front page (Index.org), both left over from the 0.136.0 flatten. Rewrote Concept.org's stale "Modelling Approach" section against the model library's actual current state. FutureResearch.org no longer keeps the full text of completed items once their outcome is recorded in ResearchJournal.org; Resuming.org and NEWS, both themselves stale, are corrected.

Version 0.136.0 (2026-09-01)
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* The whole source tree is flattened into one directory: Doc/, Doc/Illustrations/, Doc/man/, Models/, Models/Util/ and bin/ all move to the project root, distinguished by file suffix rather than by directory. The four former Makefile.am files merge into one; the HTML index-link and Emacs publish-project machinery simplify to match having one directory instead of three. A new standing rule is established: a new subdirectory is proposed, with reasons, and needs the project author's agreement before it is created.

Version 0.135.0 (2026-08-31)
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* orgdoc-lint's OD001 check (bare-underscore subscript hazard) is now opt-in rather than run by default, now that every document's own "#+OPTIONS: ^:{}" removes the hazard project-wide. Already-wrapped identifiers are unaffected and were not touched.

Version 0.134.0 (2026-08-17)
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* Every document's preamble gains "#+OPTIONS: ^:{}", stopping Org from misreading a bare underscore as a subscript --- the root cause the orgdoc-lint tilde-wrapping convention existed to work around. The HTML index/home link is now configurable at build time (./configure INDEX=...).

Version 0.133.1 (2026-07-09)
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* A stale HTML export archive left over from an earlier version no longer survives "make maintainer-clean". Every attachable model's API documentation now lists its anchor / spin / orient parameters explicitly, with defaults.

Version 0.133.0 (2026-07-09)
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* bsppfit_hexbush's through-bore now steps between the male and female ports' own diameters instead of running one uniform width throughout, matching commercial hex bushings.

Version 0.132.1 (2026-07-02)
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* Fixed bsppfit_nipple: a female or mixed-gender nipple could leave small solid fragments disconnected from the body at both tips.

Version 0.132.0 (2026-07-01)
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* The illustration pipeline's re-point to the mono-file is complete: every documentation figure is now rendered from bsppfit.scad, and the per-model render-variant build targets are retired or re-pointed accordingly.

Version 0.131.0 (2026-07-01)
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* The nine non-branched fittings' default (and default-cut) manual figures are now rendered from the mono-file.

Version 0.130.0 (2026-07-01)
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* The Manifold archetype gallery in the manual is now rendered from the mono-file.

Version 0.129.2 (2026-07-01)
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* Fixed bsppfit_union: the two tails now assemble correctly from separately printed parts.

Version 0.129.1 (2026-07-01)
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* Documentation hygiene pass: consistent assistant credit, ChangeLog trim, provenance cleanup in the Taxonomy.

Version 0.129.0 (2026-07-01)
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* Closed the mono Manifold's remaining API gap: per-end run gender, per-side branch gender, arm length, and a point-style Y-fan end are now all first-class parameters.

Version 0.128.0 (2026-06-30)
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* The HoseTail archetype gallery is now rendered from the mono-file, completing the per-gallery illustration re-point. The mono hose tail gained the barb profiles ("shark_fin", "stepped", "christmas_tree") and body shapes ("round", "hex") of the dedicated model; the default hose tail is now the shark-fin barb.

Version 0.127.0 (2026-06-30)
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* The mono union is now the full captive-nut assembly. bsppfit_union was reshaped from the simplified ring-collar body into a threaded tail, a seated tail and a hex ring nut that draws them together against a cone seat --- matching the dedicated model. New parameters expose the coupling thread and the body and collar lengths; the default union is now male-male. The Union gallery reflects the detailed form.

Version 0.126.0 (2026-06-30)
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* The Union archetype gallery in the manual is now rendered from the mono-file. The mono union gained per-end genders (gender_a, gender_b) in place of the single gender, and an explode parameter that pulls the two tails apart from the central nut for an assembly view. The default (both ends female, assembled) is unchanged.

Version 0.125.1 (2026-06-30)
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* The Elbow archetype cut-gallery now cuts from the FRONT too. In 0.125.0 it had been left on BACK on the mistaken belief that its camera (30,315) made it exempt; it was not, and the section was hidden behind the solid half like the other six.

Version 0.125.0 (2026-06-30)
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* The swept elbow introduced in 0.124.0 was stoppered --- its arm bores ran the wrong way and left both barrels solid. The bore now runs continuously from one mouth, through the bend, to the other.

* The Cap, Reducer, Nipple, HexBush, Plug and Pipe archetype cut-galleries in the manual now cut from the FRONT, so the bore and internal threads face the reader; previously the solid back half hid the section. The Elbow cut-gallery was already correct.

Version 0.124.0 (2026-06-30)
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* The Elbow archetype gallery in the manual is now rendered from the mono-file. To match the per-model Elbow (and real commercial elbows), bsppfit_elbow has been reshaped from a mitred junction into a smooth swept bend --- a quarter-torus at 90 degrees, a torus arc of (180 - angle) in general --- with the bore following the bend as a swept arc. The elbow now exposes single-port arm_length, arm_od, bore, thread_length and a new bend_radius parameter (the unused per-arm _a/_b parameters are gone). Arm A now runs +Z. The elbow, usage and usage-cut renders change accordingly; all other fittings are unchanged.

Version 0.123.0 (2026-06-30)
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* The Pipe archetype gallery in the manual is now rendered from the mono-file. The mono pipe gained a length convenience parameter (each arm becomes length/2) so the gallery's length sweep reproduces; pipes built from the per-end arm lengths are unchanged.

Version 0.122.0 (2026-06-29)
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* The Plug archetype gallery in the manual is now rendered from the mono-file. The mono plug gained a thread_length override (defaulting to the size-derived length) so the gallery's thread-length sweep reproduces; plugs at the default length are unchanged.

Version 0.121.0 (2026-06-29)
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* The HexBush archetype gallery in the manual is now rendered from the mono-file. Doing so surfaced and fixed a defect in the mono hex bush: a bushing whose female end is larger than its male end was rendered as a thin ring with no male spud, because its body and bore were sized from the wrong end. Male-larger bushings are unchanged.

Version 0.120.0 (2026-06-29)
============================

* The Cap, Reducer and Nipple archetype galleries in the manual are now rendered from the mono-file, continuing the move of the figures off the legacy per-model models; they reproduce the same archetypes in the same layout. The manual's index now also links its reference section to the model library, which is itself project reference material.

Version 0.119.0 (2026-06-29)
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* The Manifold figures in the manual --- the basic manifold, the tee and the cross, each also as a cutaway --- are now rendered from the mono-file, so they show the branch-junction reinforcement the library applies. The other figures (the per-model archetype galleries and the non-branched fittings) still render from the legacy per-model models and are unchanged; the mono-file and the per-model models build those identically apart from the reinforcement, which only the branched manifolds carry.

Version 0.118.1 (2026-06-29)
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* Fix a reducing branch (a smaller branch reinforced with a cove) whose mouth was sealed and whose thread sat set back from the tip: the cove was built a run-radius too long and the surplus was solid past the bore. The cove now stops at the branch tip. Same-size branches (a boss) were never affected, so every named fitting is byte-identical to 0.118.0.

Version 0.118.0 (2026-06-28)
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* The branch-junction reinforcement is now wired into the generic body builder and ON by default: every tee, cross and manifold branch is reinforced against its run with an external boss or cove and, for a reducer bore, an internal flare. The three branched fittings and the four mono-file galleries change shape by design; all other fittings are unchanged, and every functional mate/bore dimension is identical (parts still mate). Set BSPPFIT_BRANCH_FILLET=false to opt out. The committed doc illustrations are rendered from the legacy per-model files, which do not carry the reinforcement, so depicting it in the manual awaits an illustration-source decision.

Version 0.117.0 (2026-06-28)
============================

* The optional branch-junction fillet (still OFF by default and not yet applied to any fitting) is now angle-aware, so an angled branch (a lateral) no longer overflows: the cove/boss choice and the boss size are corrected for the branch lean, with a configurable shallowest-lean clamp (BSPPFIT_FILLET_MIN_LEAN, default 45 degrees). Every existing fitting still renders exactly as before.

Version 0.116.1 (2026-06-28)
============================

* The optional branch-junction fillet (still OFF by default and not yet applied to any fitting) no longer cusps at a same-size junction: the same-size case now uses a strength boss with a rounded shoulder instead of a cove. Reducers are unchanged. Every existing fitting still renders exactly as before.

Version 0.116.0 (2026-06-28)
============================

* New optional branch-junction fillet for FDM strength, OFF by default and not yet applied to any fitting. This step lands the helper bsppfit_branch_fillet() and its configuration (BSPPFIT_BRANCH_FILLET and the fillet-size and segment constants), exercised on a test grid (render="fillet-grid" in the test driver). Every existing fitting renders exactly as in 0.115.3.

Version 0.115.3 (2026-06-28)
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* Documentation only: the research journal and future-research notes now record the chosen branch-junction fillet method --- a rounded cove on reducers, a strength boss at same-size branches, and sharp internal bores --- and the plan to integrate it later behind a default-off flag. No model or geometry change; every fitting renders identically to 0.115.2.

Version 0.115.2 (2026-06-27)
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* The bore-junction blend is gone: tee, cross and manifold junctions are now left at bore level, keeping the wall material the blend removed. Bores still meet cleanly through the transition hull and the run bore.

Version 0.115.1 (2026-06-27)
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* Manifold bore junctions are cleaner: the blend that rounds where a branch meets the run is now a tight fillet at the branch points only, instead of a wall-sized sphere at every port. The run ends and a sealed header end keep their material. The fillet size is tunable via the new BSPPFIT_BRANCH_BLEND constant (1.0 suppresses it entirely). Tee and cross are unchanged.

Version 0.115.0 (2026-06-26)
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* A "closed" port is now a thread-less, rounded, integral seal --- the blanked end of a manifold header or a dead-leg --- instead of a threaded port with a merely blocked bore. Manifold headers and dead-legs now read as proper sealed ends.
* Caps and plugs are unchanged in appearance: they are open threaded ports finished with a sealing head, so they keep the thread that lets them mate.

Version 0.114.2 (2026-06-26)
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* Clearer model API examples: the hex bush's second example is shown from the female end so its socket is visible, and the nipple and elbow second examples are now male-to-female.
* In the API HTML, the author block now sits at the foot of the page, matching the other documents.

Version 0.114.1 (2026-06-26)
============================

* "make html" and "make pdf" now build the model API reference (the HTML and the PDF respectively), so the documentation-index link to it resolves; previously only "make html-export" produced them.
* configure now checks for the luaotfload lualatex font loader that every PDF build requires.
* The author credit reads "assisted by ..." consistently across the documents and the API reference.

Version 0.114.0 (2026-06-26)
============================

* The model API documentation is now produced as a single consolidated HTML page and a PDF ("make api-doc"), linked from the documentation index and bundled into the HTML export for the HTTP server. The HTML carries the Index back-link, the authoring and version block, and a link to the PDF.
* "make clean" now also removes the generated docsgen wiki (Doc/api.wiki) and the API HTML/PDF.

Version 0.113.4 (2026-06-26)
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* The public API is now documented: the dimension lookups and the cutaway operator with full reference blocks, the port-list builders with one-line summaries. This completes the openscad-docsgen documentation rollout.

Version 0.113.3 (2026-06-26)
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* The bsppfit() super-class is now documented, including the port-list representation that drives it.

Version 0.113.2 (2026-06-26)
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* The decorations (hex bush, hose tail, union, cap, plug) are now documented to the openscad-docsgen standard.

Version 0.113.1 (2026-06-25)
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* The catalogue fittings (pipe, nipple, elbow, tee, cross, reducer, manifold) are now documented to the openscad-docsgen standard, with cross-references between them.

Version 0.113.0 (2026-06-25)
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* The docs-check tool and the "make docs-check" target are renamed to model-doc-check.
* New "make model-docs" target generates the rendered API documentation for visual review.

Version 0.112.1 (2026-06-25)
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* The docs-check tool gains a man page and now finds openscad-docsgen in ~/.local/bin.

Version 0.112.0 (2026-06-25)
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* New "make docs-check" target checks the API documentation against the BOSL2 openscad-docsgen standard; bsppfit_pipe is the first module documented to it.

Version 0.111.6 (2026-06-25)
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* The test grid's eccentric reducer now uses the bsppfit_reducer() wrapper.

Version 0.111.5 (2026-06-25)
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* Eccentric reducer bore: the bore now breaks through flush at both ports; the lofted end caps no longer cant short of the tip faces.

Version 0.111.4 (2026-06-12)
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* Reducer bore: concentric and eccentric reducers now taper through a smooth loft instead of a scooped sphere.

Version 0.111.3 (2026-06-12)
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* Elbow bore: the residual sphere at the bend junction is gone; the bore is now purely the swept torus.

Version 0.111.2 (2026-06-12)
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* Elbow bore: an elbow's bore now curves through the bend as a constant-width swept torus instead of a sphere scooped at the junction. The old sphere removed far more than the bore needed --- thinning the wall and pocketing the flow; the new bend keeps full wall thickness and a smooth channel. Only the elbow changes; all other fittings are unaffected.

Version 0.111.1 (2026-06-12)
============================

* bsppfit_nipple: a female end now keeps a proper wall around its internal thread (it rendered paper-thin before); the male-male nipple is unchanged. A close nipple (middle_length = 0) is no longer accepted --- use bsppfit_pipe for a plain short connector.
* Test area: the cap and plug cells now exercise the bsppfit_cap/bsppfit_plug sub-classes, and a male elbow and male cross were added.

Version 0.111.0 (2026-06-12)
============================

* New bsppfit_manifold() wrapper builds a manifold --- a run carrying a family of branches (branch_count at a given pitch, on one side or both, with per-side lean and closable run ends). Completes the set: every catalogue topology now has a named wrapper.

Version 0.110.0 (2026-06-12)
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* New bsppfit_cross() wrapper builds a cross --- a straight run plus two opposite branches (default 90 degrees). Run and branches may differ in size (a reducing cross) and gender; per-group arm, bore and thread overrides.

Version 0.109.0 (2026-06-12)
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* New bsppfit_tee() wrapper builds a tee --- a straight run plus one branch (default 90 degrees). Run and branch may differ in size (a reducing tee) and gender; per-group arm, bore and thread overrides.

Version 0.108.0 (2026-06-12)
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* New bsppfit_elbow() wrapper builds an elbow --- two same-size ports meeting at an angle (default 90 degrees). Per-end gender, arm length, arm OD, bore and thread length; the angle generalises beyond the fixed 90-degree dedicated model.

Version 0.107.0 (2026-06-12)
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* New bsppfit_nipple() wrapper builds a nipple --- two same-size threaded ends joined by a short hex (or round) wrench-grip middle section. Per-end gender, thread length and bore; middle_length 0 makes a close nipple.

Version 0.106.0 (2026-06-11)
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* bsppfit_reducer() now draws the hexagonal wrench-grip body (hex_ports = "large", "small" or "both").
* New bsppfit_pipe() wrapper builds a pipe from named per-end parameters (gender, arm length, arm OD, bore, thread length per end).

Version 0.105.0 (2026-06-11)
============================

* bsppfit() now accepts per-port arm_length, arm_od, bore and thread_length: pass a scalar for all ports, or a list of one value per port.
* New bsppfit_reducer() wrapper builds a reducer from named per-side parameters (sizes, genders, arms, bores, eccentric) instead of a hand-written port list.

Version 0.104.4 (2026-06-11)
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* The core bsppfit() module now documents all of its parameters inline.

Version 0.104.3 (2026-06-11)
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* Recorded the decision to add snake-named wrapper modules (e.g. bsppfit_reducer) over the super-class, with a worked per-port example, in the future-research notes.

Version 0.104.2 (2026-06-11)
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* Added a future-research analysis of how catalogue fittings are instantiated through the bsppfit super-class versus the dedicated models.

Version 0.104.1 (2026-06-11)
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* Models/bsppfit.scad is now a definitions-only library, safe to include into another project; its galleries, render dispatch and test grid move to a new Models/bsppfitTest.scad.
* Taxonomy references to the mono-file use its current name, bsppfit.scad.

Version 0.104.0 (2026-06-11)
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* The mono-file is renamed Models/Fitting.scad to Models/bsppfit.scad, with its own names prefixed bsppfit/bsppfit_ for namespace isolation.

Version 0.103.0 (2026-06-10)
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* Models/Fitting.scad carries the Util/util.scad helpers inline; the helper file is kept for the other models.

Version 0.102.3 (2026-06-10)
============================

* There is now a single cutaway mechanism: the decoration sub-classes (cap, plug, hex bush, hose tail, union) section through the same bsppfit_cutaway operator as the rest of the library, removing the duplicate mask.
* The eccentric reducer is rounded: its internal bore now tapers smoothly between the two sizes instead of stepping sharply, and its exterior tapers without the sphere bulge that sat at the inflection.

Version 0.102.2 (2026-06-10)
============================

* Rendering the test area no longer emits warnings: the bore junction blend introduced in 0.102.1 referred to a variable outside its scope; it now computes the arm size locally.
* The cutaway direction is corrected at its source (bsppfit_cutaway): cutaway = FRONT opens the front, and likewise for the other directions, consistently for both the mono-file core and the dedicated models.

Version 0.102.1 (2026-06-10)
============================

* The bore is now rounded where it bends: at an elbow (or any branch meeting the run at an angle) the inner corner of the bore was a sharp re-entrant vertex that would restrain flow; a junction blend now gives a smooth concave inflection. Mate dimensions are unchanged.

Version 0.102.0 (2026-06-10)
============================

* Angled-branch (Y-fan) clearance is now enforced, not just advised: fitting_yfan_ports builds a Y whose run is automatically long enough that a fitting on the run port clears the leaning branch, and fitting_manifold_ports extends its run ends the same way. The reach adapts to the branch angle, length, and position.
* The cap and plug decorations are completed: fitting_cap and fitting_plug add the commercial wrench head (hex by default, or round), reproducing the dedicated Cap and Plug in full --- mate dimension and head alike. With this, every dedicated model's decoration is available from the mono-file. The equivalence test now covers thirteen cases, all passing.

Version 0.101.1 (2026-06-10)
============================

* Two-sided manifolds (fitting_manifold_ports with branch_sides = "both") now place branches on both sides of the run; previously all branches landed on one side. Perpendicular and one-sided manifolds are unchanged.
* The mixed-Y test fitting is now genuinely assemblable: a branch that leans toward a run end needs the run long enough on that side, or a fitting on the run port collides with the branch. The minimum run reach depends on both the branch's reach and its position along the run; this is now documented.

Version 0.101.0 (2026-06-10)
============================

* The Fitting cutaway direction is reversed so it finally reads naturally: cutaway = FRONT opens the front, cutaway = BACK opens the back. (The 0.100.0 attempt was still inverted.) Callers passing an explicit cutaway direction will see the opposite of the 0.100.0 behaviour.
* In the Taxonomy bibliography, the engineering-reading entry is now a sub-list: the Cross (1936) hydraulic-network reference and the Weiler (1985) solid-modelling reference each have their own sub-item.

Version 0.100.0 (2026-06-10)
============================

* The Fitting cutaway parameter now follows the natural reading: cutaway = FRONT opens the front, cutaway = BACK opens the back. Previously the named direction and the opened face were reversed. Callers that passed an explicit cutaway direction will see the opposite (named) side opened --- the intended correction.
* The Fitting test area gains a fifth row, so it now exercises every fitting the mono-file produces: the eccentric reducer and the three decoration sub-classes (hex bush, hose tail, union) join the existing grid.

Version 0.99.2 (2026-06-10)
===========================

* The Topological Foundations part of the Taxonomy now cites two concrete, significant sources for the engineering reading --- Hardy Cross (1936) for the pipe-network-as-graph view and Kevin Weiler (1985) for the face-adjacency-graph view of solids --- alongside the existing framing. Within that part, the inline bibliography links now point to the Bibliographic references (Topological Foundations) subsection rather than to the whole Sources and Attributions section.

Version 0.99.1 (2026-06-10)
===========================

* The two-tier equivalence test now covers all eleven trade categories, not just the pilot pipe, and every case passes: the mono-file Models/Fitting.scad reproduces the functional geometry (thread and bore dimensions that decide whether parts mate) of each dedicated reference model, to within 0.05 mm. Two decorations remain noted for the migration's completion: the wrench head on the dedicated Cap and Plug, which the basic mono-file cap/plug does not carry (the mate dimensions still match).

Version 0.99.0 (2026-06-09)
===========================

* New tool bin/equivalence-test: a two-tier harness that checks the mono-file Models/Fitting.scad against the dedicated reference models --- Tier 1 compares the functional dimensions that decide whether parts mate (thread major Ø, bore Ø) measured from rendered STLs; Tier 2 renders side-by-side stills. A "make check-equivalence" target runs it. The harness is proven on the straight-pipe facet, where the mono-file matches the reference exactly; the remaining categories are added as registry entries.

Version 0.98.0 (2026-06-09)
===========================

* The mono-file model is complete: Models/Fitting.scad now produces all eleven trade categories from one file. The last three --- the hex bush, hose tail and union, which add a wall or assembly decoration the port list does not carry --- are folded in as thin sub-class modules (fitting_hexbush, fitting_hosetail, fitting_union). The dedicated model files are retained for now as the reference oracle for the equivalence test to come.

Version 0.97.0 (2026-06-09)
===========================

* The single-ancestor question, deferred for six iterations, is settled: the BSPP catalogue has one common ancestor --- the parametric genus-zero family --- which is why a single parametric core can generate every trade category. This is the architectural basis for the forthcoming mono-file model.
* The two standalone topology documents are merged into a new Topological Foundations part of the Taxonomy, the catalogue's theoretical foundation. The separate Topology.org and TopologyRigorous.org are withdrawn; the source-document count drops from eleven to nine.

Version 0.96.0 (2026-06-09)
===========================

* The topology documents now carry inline reference attributions at each borrowed claim, linking to a References section; Topology.org gains its own References section.
* The Fitting super-class places an angled branch correctly: an arm-length clearance term keeps an oblique branch's mouth clear of the run.
* fitting_manifold_ports now builds two-sided manifolds with differing top and bottom branch angles (top + bottom = 180 gives the X-form), following the Manifold branch-angle convention.

Version 0.95.0 (2026-06-09)
===========================

* The experimental Fitting super-class now expresses multi-branch manifolds: a per-port offset carries branch position, which is a decoration (topologically the branches slide freely along the run) rather than a change of fitting. A single code path now covers cap, plug, pipe, elbow, reducer, tee, cross and the multi-branch manifold, plus fittings beyond the catalogue. Its test area is now a full grid of the significant combinations.
* The straight facet of the Taxonomy gains the Pipe model's archetype gallery illustration, which was missing.
* The rigorous topology document gains a bibliography (cobordism, Frobenius-algebra and surface-classification references) and records the working hypothesis that each named fitting is a thin sub-class of the super-class --- the route toward a single model file.

Version 0.94.0 (2026-06-09)
===========================

* New experimental model Fitting (Models/Fitting.scad): a decorated super-class driven by a port list, from which a single code path produces cap, plug, pipe, elbow, reducer, tee and cross --- and fittings beyond the catalogue, such as a branch at an arbitrary angle with mixed gender and size on one body. It is the working experiment behind the topological single-ancestor question (see TopologyRigorous); it is not the model of record for any trade category, pending an architectural decision. A "usage" render variant lays out the facets side by side for review. The topological grouping is subsumed cleanly; engineering decorations the port list does not carry (a hex grip, a hose barb, a union's detachable pieces, multi-branch manifolds) mark where the dedicated models still apply.

Version 0.92.0 (2026-06-08)
===========================

* New document Topology: a rigorous pass (Doc/TopologyRigorous.org). It builds the fitting cobordism category precisely and proves what the earlier exploration could only conjecture: port count is a complete topological invariant of the (genus-zero) fittings, and every fitting is a composition of pipe, tee and cap, with the tee/cross/manifold merge a corollary. It also reports the first concrete evidence on the "is the manifold the ancestor" question, while keeping that decision formally deferred --- its exit condition now being the clean construction of a single decorated parametric fitting class.

Version 0.91.0 (2026-06-08)
===========================

* The Pipe model now has working render targets: "make render-Pipe", "make render-Pipe-sphere" and the variant and archetype targets, which were missing after the model was added in 0.89.0. The Pipe also gains a full twelve-configuration archetype gallery (and a sectioned companion), matching the other models.
* The Topology document gains a prior-art survey (relating the study to cobordism theory and to pipe-network graph models) and a plan for the rigorous second pass; the manifold-ancestor decision remains deferred.

Version 0.90.0 (2026-06-08)
===========================

* New document Topology (Doc/Topology.org): an exploration of the fitting set through a topological lens --- the fluid path and the solid body in parallel --- identifying port count as the deformation invariant, showing the two-port fittings are deformations of a pipe while terminations and branchings require a surgery, and laying out (without yet deciding) whether the manifold is the common ancestor.
* orgdoc-lint now exempts LaTeX math spans from its content checks: a backslash-command or underscore inside \( \), \[ \] or $ $ is no longer flagged.

Version 0.89.0 (2026-06-08)
===========================

* New model Pipe (Models/Pipe.scad): a length of pipe of a given overall length, with an independently gendered BSPP port (male thread or female socket) at each end and a through-bore. Joins the Nipple in the straight (G-01) family.
* orgdoc-lint can now correct, not just report: "orgdoc-lint --fix" wraps underscore identifiers (OD001) and converts literal primes (OD006) in place. The fragile-span codes are still reported only. New "--diff" and "--format=json" options support previewing and tooling.

Version 0.88.0 (2026-06-06)
===========================

* New tool bin/orgdoc-lint: a linter that reports Org-mode markup hazards (subscript-inducing underscores, malformed verbatim spans, bare backslash-commands, literal primes) before they reach the PDF/HTML build. Run it with "make lint", "make lint-errors", or "make check-org"; see orgdoc-lint(1).
* All documentation is now free of subscript-leak and other error-severity markup hazards.

Version 0.87.1 (2026-06-05)
===========================

* Research journal: identifier names with underscores now render correctly in body text (no longer mangled into subscripts).

Version 0.87.0 (2026-06-05)
===========================

* Models with a male thread now accept a male_slop parameter that adds a clearance allowance to the external thread (for heterogeneous fits such as a printed male into a metal female). Default 0 leaves prints unchanged.
* The HTML author metadata tag is now clean plain text.

Version 0.86.0 (2026-06-05)
===========================

* Document title blocks now name the assistant on a second line, under the author, in both PDF and HTML.

Version 0.85.0 (2026-06-03)
===========================

* Fixed the checkmark (✓) character mapping in the documentation.
* Underscore identifiers in research-journal section titles now render in monospace, not as subscripts.

Version 0.84.0 (2026-06-03)
===========================

* Models/Util/bsppfit_threading.scad now works under "use", not only "include".
* Print Tuning Log: added bench-measured male_slop clearances (G1/2, PETG) and a thread-sealing paste note.

Version 0.83.0 (2026-06-02)
===========================

* Models call bsppfit_threaded_rod() at every thread site (behaviour-preserving; prints unchanged).

Version 0.82.0 (2026-06-02)
===========================

* Added Models/Util/bsppfit_threading.scad, a forked BSPP threading module with a male_slop external-thread clearance parameter.

Version 0.81.0 (2026-06-02)
===========================

* Added a manual page for bin/man2htmldoc.
* Documented heterogeneous (mixed-material) thread fits and the male-thread clearance approach.

Version 0.80.0 (2026-06-02)
===========================

* The PDF documentation no longer emits a "Missing character ... fontspec" warning: two symbols (element-of and white square) that the main font lacks are now mapped to their LaTeX equivalents.
* The manual-page HTML converter is now bin/man2htmldoc (renamed from a .sh helper and moved beside the other command-line tools), keeping a distinct name from the system man2html.
* configure now checks for groff and warns if it is missing (groff is needed only to build the manual-page HTML).

Version 0.79.0 (2026-06-01)
===========================

* The HTML documentation now includes the manual pages for the command-line tools (checkxref, applyxref, render-views), reachable from the documentation index.
* New "Print Tuning Log" in the Development Standard collects the per-material, per-printer tweaks (such as the female-thread clearance) needed to print fittings that mate with commercial ones.
* Documented that BOSL2's $slop clearance applies to internal (female) threads only; an external (male) thread is unaffected by $slop, so a male fit is tuned by other means.
* The French bilingual glossary now cites André Chevalier's Guide du dessinateur industriel for the "profil gaz" terminology, and notes that the same thread is named for its British origin in English and its gas-piping use in French.

Version 0.78.0 (2026-06-01)
===========================

* FutureResearch and the ResearchJournal now record the BOSL2 documentation-build process (the openscad-docsgen pipeline, its failure modes and fixes, and the doc-block grammar), as preparation for a possible future contribution of the BSPPFit models upstream into BOSL2.

Version 0.77.0 (2026-06-01)
===========================

* Taxonomy: the Validation Scenarios chapter now appears just before the Glossary (after the coverage and audit chapters) instead of immediately after the facets, so the worked examples no longer compete with the taxonomy's definitional core for emphasis.

Version 0.76.0 (2026-06-01)
===========================

* All PDFs build cleanly again: the spurious "produced with errors" message (duplicate hyperref destinations) is gone.
* All tables break across pages (longtable), removing the large gaps left by whole-table page breaks.
* Three latent LaTeX errors fixed in the ResearchJournal and FutureResearch journal entries.
* The illustration Catalogue builds without errors; remote source URLs are now plain hyperlinks, not failed image embeds.
* Taxonomy no longer prints two Lists of Tables.
* Every document's PDF carries its table of contents under the standard make/latexmk build (the TOC needs more than one LaTeX pass; a single manual run shows none).

Version 0.75.0 (2026-06-01)
===========================

* PDF page headers no longer overflow or overlap with long section names: headers now show a single truncated, mixed-case mark on the outer corner of each page (applied to all documents via the shared preamble).
* Table fixes: the BSPP-designator table (Table 22) now has correctly proportioned columns; the Sources-and-Attributions credits table (Table 23) no longer overlaps its first two columns; the long geometric-fittings bilingual table (Table 14) now continues across pages via longtable.
* The illustration Catalogue (Doc/Illustrations/Catalogue.org) now builds to PDF in the standard chain; the org-persist download loop that previously blocked it is fixed.

Version 0.74.0 (2026-06-01)
===========================

* Fixed the remaining table overflows in the PDF: the bilingual glossary tables (geometric types, gender, sealing, materials, pressure, approvals, tools, adjacent systems, and the BSPP designator cross-reference) now use width-constrained wrapping columns and a smaller font. The section 16 "Sources and Attributions" credits table also gained a caption and a wrapping layout. A full build now shows no large table overflows.

Version 0.73.0 (2026-05-31)
===========================

* configure now checks for ImageMagick convert (or magick), required by the illustration whitespace-trim step in make render-archetype-stills.
* Fixed table overflow/dilation in several tables: the per-size dimension tables (BSPP/BSPT/NPT) got shorter column headers; the dense application-context, Wikipedia-coverage, and bilingual thread-form tables got width-constrained wrapping columns and smaller fonts. The section 13.4 facet-by-facet audit table also gained its missing caption. (Further dense bilingual tables remain to be reviewed.)
* The assistant name and version now appear under the author in both the HTML and PDF title blocks.

Version 0.72.0 (2026-05-31)
===========================

* Trimmed the whitespace around all illustrations: the rendered stills are now cropped to their content with a uniform margin, so the fittings fill the figures (content was only 19-32 % of the frame before). Galleries in particular are much larger and clearer, and the [H]-placed figures leave smaller page gaps.
* The trim is a reproducible step in the render-archetype-stills target (deterministic, -strip'd), so the committed illustrations stay byte-identical to a fresh render.

Version 0.71.0 (2026-05-31)
===========================

* Gender illustration (zone A): the Gender facet (F-02) now carries a geometry-level comparison of a male fitting and a female fitting (G-01 family), solid + cutaway (M-11), showing the external-vs-internal thread distinction. This completes the illustration programme (zones A, B, C and the cross-reference pass).
* New render variants gender-comparison and gender-comparison-cut (two-fitting side-by-side scenes) added to Nipple.scad.

Version 0.70.0 (2026-05-31)
===========================

* HTML: the list of tables is now unfolded, matching the list of figures (removed the collapsible <details> wrapper around #+TOC: tables in Taxonomy.org).
* Fixed the Tee and Cross glossary illustrations, which referenced the wrong file names (Manifold-tee-default.png instead of Manifold-tee.png, and likewise for cross and the cutaways).
* PDF: figures are now anchored at their point of definition (figure environment forced to [H] placement in the preamble), so the geometry galleries render within their G-NN sections instead of floating to later pages.

Version 0.69.0 (2026-05-31)
===========================

* End-of-zone-B cross-reference pass: the Validation Scenarios now link to the relevant geometry figures (hose tail, hex bush, union, reducer, tee) where the figure supports the scenario's reasoning, improving navigability from prose to illustration.

Version 0.68.0 (2026-05-31)
===========================

* Glossary illustrations (zone C): each of the eleven fitting-type glossary entries (Nipple, Elbow, Cap, Plug, Union, Reducer, Hex bush, Hose tail, Manifold, Tee, Cross) now carries an inline single-fitting render, solid + cutaway (M-10).
* New render variant default-cut added to each model (the default fitting with cutaway = BACK); Manifold also gains tee-cut and cross-cut.

Version 0.67.0 (2026-05-31)
===========================

* Taxonomy integration: Manifold (G-10) archetype-gallery stills added as figures (M-09). This completes the zone-B geometry galleries (all ten facets illustrated).
* The Manifold gallery also illustrates the Tee (G-03) and Cross (G-04) configurations (first two cells); their taxonomy entries now cross-reference these figures.
* Manifold cutaway gallery cut BACK (was FRONT) so the run bore and branch-to-run junctions read at the still viewpoint.

Version 0.66.0 (2026-05-31)
===========================

* Taxonomy integration continued: Union (G-07) archetype-gallery stills added as figures (M-08). Last standalone geometry facet; only G-10 Manifold (with its Tee/Cross degenerates) remains.
* Union cutaway gallery cut BACK (was FRONT) so the internal conical seat, bore continuity, and exploded three-piece construction read at the still viewpoint.

Version 0.65.0 (2026-05-30)
===========================

* Taxonomy integration continued: Hex bush (G-08) archetype-gallery stills added as figures (M-07).
* Hex-bush cutaway gallery cut BACK (was FRONT) so the through-bore and the diameter step at the gender transition read at the still viewpoint.

Version 0.64.0 (2026-05-30)
===========================

* Taxonomy integration continued: Hose tail (G-09) archetype-gallery stills added as figures (M-06).
* Hose-tail cutaway gallery cut BACK (was FRONT); the cut also carries the barb-profile detail that is subtle on the solid exterior at grid scale.

Version 0.63.0 (2026-05-30)
===========================

* Taxonomy integration continued: Cap (G-06) and Plug (G-06) archetype-gallery stills added as figures (M-04, M-05). G-06 is the one geometry facet with two model files, so both are done together and the entry carries four figures.
* Cap and Plug cutaway galleries cut BACK (was FRONT) so the cap's internal female bore and the plug's solid shaft read at the still viewpoint.

Version 0.62.0 (2026-05-30)
===========================

* Taxonomy integration continued: Reducer (G-05) archetype-gallery stills added as figures (M-03).
* HTML documents now include a list-of-figures (mirrors the existing list-of-tables; Org has no native figures TOC, so it is synthesised during HTML export).
* Doc/SessionHandoff.org (session continuity record) now ships in every distribution.
* configure.ac: dropped the unused Doc/Illustrations/Makefile from AC_CONFIG_FILES (no SUBDIRS recursion into that directory); fixes make distcheck.

Version 0.61.0 (2026-05-30)
===========================

* Taxonomy integration continued: Straight (G-01) archetype-gallery stills added as figures (M-02).
* PDF build fixes: Taxonomy (U+2033 inch mark -> ASCII), FutureResearch (stray U+0008 -> \b), ResearchJournal (quoted old table wrapped in example block).
* make dist now preserves the M-NN illustration symlinks as symbolic links (automake tar -h dereference disabled).

Version 0.60.0 (2026-05-30)
===========================

* Taxonomy integration begun: archetype-gallery stills now appear as figures. Elbow (G-02) is the first entry.
* render-views: new --still LAT,LON (single coordinate-encoded frame; not combinable with --mp4/--tar/--label-frames) and --colorscheme NAME (off by default).
* New "make -C Models render-archetype-stills" target.
* Doc/Illustrations carries model-render stills as M-NN catalogue slots; the Taxonomy references a stable name that is a symlink onto the chosen frame.
* Taxonomy Geometry Facet enumeration is now per-entry subheadings (G-01..G-10).
* Elbow archetype cutaway gallery cut BACK (was FRONT). No model API changed.

Version 0.59.0 (2026-05-29)
===========================

* Cutaway parameter now takes BOSL2 axis-direction vectors instead of strings.
* cutaway = "front" becomes cutaway = FRONT; "left" -> LEFT; etc.
* cutaway = "none" becomes cutaway = undef (the new "no cutaway" sentinel).
* The string form is no longer accepted (clean break per Constitution).
* Migration: "none" -> undef, "left" -> LEFT, "right" -> RIGHT, "front" -> FRONT, "back" -> BACK, "bottom" -> BOTTOM, "top" -> TOP.

* Taxonomy: Manifold glossary entry rewritten to carry both the trade sense (multi-branch distribution) and the project's unified-class sense (G-10 subsumes tee, cross, multi-branch manifold).
* Taxonomy: G-10 catalogue entry now links to the glossary (closing the back-link gap that made the entry hard to find).

* No model geometry, no model API beyond the cutaway parameter, changed.

See the 0.59.0 ResearchJournal entry for the decisions
(undef vs named-constant, clean-break vs dual-acceptance,
axis-only vs arbitrary vectors).

Version 0.58.0 (2026-05-29)
===========================

* Model directory hierarchy flattened: all nine model files now live directly under Models/ (Models/Elbow.scad, Models/Nipple.scad, etc.).
* The G0n_<Class>/ per-G-facet subdirectories are removed.
* Util/ kept as a directory (shared infrastructure: dimensions.csv + util.scad).
* Render output moved to Models/Renders/<ModelName>/ --- one subdirectory per model under a single top-level Renders/.
* Variants of the same model share their model's Renders subdirectory; PNG/tar/MP4 filenames remain variant-prefixed.
* Taxonomy ↔ model file mapping table added to Models/LibraryOverview.org (the home for the information the directory names used to carry).
* No model API or rendered geometry changed.
* Users invoking bin/render-views directly need to update --scad-file and --output-dir paths; Makefile users are not affected beyond the new output location.

See the 0.58.0 ResearchJournal entry for the
input-flatten-implies-output-restructure reasoning.

Version 0.57.0 (2026-05-28)
===========================

* New "make render-archetypes" target: renders all nine models' archetype galleries (gallery-archetypes + gallery-archetypes-cut, 1600x1200) in one invocation.
* Parallel frame rendering: render-views gains --jobs N (render N frames at a time in independent OpenSCAD subprocesses).
* The Makefile derives the job count from make's own -j flag: "make -j4 render-archetypes" renders four frames at a time; "make -j" uses all cores; plain make is sequential.
* Parallel output is byte-identical to sequential; only wall-clock time differs.
* render-views(1) and DevelopmentStandard.org document the new flag, target, and -j semantics.

See the 0.57.0 ResearchJournal entry for the threads-vs-processes
and frames-parallel-models-sequential decisions.

Version 0.56.0 (2026-05-28)
===========================

* Nipple (straight family) gains per-port gender: gender_a and gender_b, each "M" or "F".
* M x M = nipple, M x F / F x M = adapter, F x F = socket (naming resolved and documented in the taxonomy).
* Nipple archetype gallery added: row 1 the four gender combinations, row 2 middle_shape x size, row 3 specials.
* Two new RENDER_VARIANTS entries (Nipple, solid + cutaway), both at 1600x1200.
* Taxonomy: 0.8.5 open question on female/mixed straight fittings closed; Adapter glossary entry added; Nipple/G-01 entries updated.
* Milestone: all nine models now have archetype galleries with cutaway companions --- the rollout is complete.

See the 0.56.0 ResearchJournal entry for the taxonomy
resolution and the gender-naming decisions.

Version 0.55.0 (2026-05-28)
===========================

* Archetype gallery added for HoseTail.
* HoseTail gains gallery-archetypes and gallery-archetypes-cut dispatch variants.
* 12 cells span barb_profile (shark_fin, stepped, christmas_tree), body_shape (round/hex), gender (M/F), shouldered, and barb_count.
* Two new RENDER_VARIANTS entries (HoseTail, solid + cutaway), both at 1600x1200.
* Eighth of nine models to get an archetype gallery; only the Straight-family Nipple remains without one.

See the 0.55.0 ResearchJournal entry for the five-axis cell
selection and the gallery-zoom barb-detail limitation.

Version 0.54.0 (2026-05-28)
===========================

* Elbow gains per-port gender: gender_a and gender_b, each independently "M" or "F".
* The four combinations M x M, M x F, F x M, F x F are all supported (mixed = "street elbow").
* Female ports carry a tapped socket (the Cap/Reducer/Union/HoseTail female-port idiom).
* Elbow archetype gallery reworked: row 1 now the four gender combinations, row 2 size sweep, row 3 dimensional specials.
* This corrects a 0.53.0 ordering error (the gallery was built before the model had a gender axis).

See the 0.54.0 ResearchJournal entry for the female-port
geometry and the prerequisite-verification lesson.

Version 0.53.0 (2026-05-28)
===========================

* Archetype gallery added for Elbow.
* Elbow gains gallery-archetypes and gallery-archetypes-cut dispatch variants.
* 12 cells: row 1 size sweep, row 2 bend_radius variation, row 3 arm_length variation plus larger sizes.
* The Elbow has one gender (M x M), so this gallery is a dimensional parameter sweep rather than a gender/pose archetype set.
* Two new RENDER_VARIANTS entries (Elbow, solid + cutaway), both at 1600x1200.

See the 0.53.0 ResearchJournal entry for the parameter-sweep
framing and the bend_radius/arm_length value constraints.

Version 0.52.0 (2026-05-28)
===========================

* Archetype gallery added for Union.
* Union gains gallery-archetypes and gallery-archetypes-cut dispatch variants.
* 12 cells: rows 1 and 2 mirror the four gender combinations assembled vs exploded; row 3 single pieces (tail-a, tail-b, nut) plus a larger size.
* union_tail_a, union_tail_b, union_nut gained a cutaway parameter (was previously only on the Union wrapper).
* Two new RENDER_VARIANTS entries (Union, solid + cutaway), both at 1600x1200.

See the 0.52.0 ResearchJournal entry for the pose-mirroring
design and the sub-module cutaway extension rationale.

Version 0.51.0 (2026-05-27)
===========================

* Archetype gallery added for HexBush.
* HexBush gains gallery-archetypes and gallery-archetypes-cut dispatch variants.
* 12 cells: row 1 standard M-large layout sweeping size ratios; row 2 swapped F-large layout, mirrored ratios; row 3 specials (equal-size gender-changer, tall hex, mid-range sizes).
* Two new RENDER_VARIANTS entries (HexBush, solid + cutaway), both at 1600x1200.

See the 0.51.0 ResearchJournal entry for the mirror-row design,
cell selection rationale, and HexBush-specific axes.

Version 0.50.1 (2026-05-27)
===========================

* configure.ac checks for fc-match (fontconfig) as optional, mirroring ffmpeg.
* Makefile help target's variant extraction fixed (4th colon field no longer leaks into target name).
* FutureResearch status updates compressed to one-line state changes plus a forward "Still open" list.
* Cap cutaway gallery preserved as policy: orthogonality of the archetype-gallery pattern across all models.

Bug-fix iteration. No new features, no API changes.

Version 0.50.0 (2026-05-27)
===========================

* Font for burn-in label resolved via fc-match.
* --label-font accepts a fontconfig pattern or an explicit TTF path.
* Default font family: "DejaVu Sans Mono:bold" (resolved at run time).
* Labelled-frames directory moved to <TMPDIR>/render-views-label-<pid>/.
* TMPDIR environment variable honoured (defaults to /tmp).
* Cleanup-at-exit via atexit handler.
* New --keep-labels flag suppresses cleanup for debugging.
* Archetype galleries added for Cap and Plug.
* Cap: size x head_shape x head_height; Plug: size x head_shape x thread_length.
* Four new RENDER_VARIANTS entries (Cap and Plug, solid + cutaway), all 1600x1200.
* render-views(1) updated: .Labelled section rewritten, --keep-labels documented,
  ENVIRONMENT TMPDIR added.

See the 0.50.0 ResearchJournal entry for the fc-match design,
tmpdir naming choice, --keep-labels rationale, and Cap/Plug
cell selection.

Version 0.49.0 (2026-05-26)
===========================

* burn_in_labels sweeps stale frames from .Labelled/ before each run.
* New --label-font PATH on bin/render-views overrides the default DejaVu Sans Mono Bold.
* Makefile pipeline always passes --label-frames now (every render-* target).
* Direct bin/render-views invocations remain opt-in.
* RENDER_VARIANTS entries gain an optional fourth field WxH for per-variant --imgsize.
* Four archetype-gallery variants set to 1600x1200 so threads stay readable.
* render-views(1) updated: --label-font, .Labelled cleanup note, fourth-field example.

See the 0.49.0 ResearchJournal entry for the four design choices
(cleanup scope, font default, always-label rationale, fourth-field
vs separate-variable for imgsize).

Version 0.48.0 (2026-05-26)
===========================

* New --label-frames flag on bin/render-views burns NNN+LL+LLL coordinate label into MP4 frames.
* Implementation: per-frame ffmpeg drawtext pass writing to a sidecar .Labelled/ directory.
* Original PNGs unchanged; only the MP4 frames carry the label.
* Useful for picking the best camera position in slow-motion MP4 review.
* Implies --mp4; default off.
* render-views(1) updated: --label-frames option, salient example, FILES entries.
* Reducer gains gallery-archetypes and gallery-archetypes-cut dispatch variants.
* 12-cell archetype gallery for Reducer: gender row, hex_ports row, eccentric row.
* Two new RENDER_VARIANTS entries for Reducer.

See the 0.48.0 ResearchJournal entry for the burn-in design (per-
frame vs single-pass ffmpeg, sidecar vs in-place, font choice)
and the Reducer cell selection rationale.

Version 0.47.0 (2026-05-26)
===========================

* Manifold combinatorial gallery redesigned: axis-matrix replaced by archetype gallery.
* New: gallery-archetypes shows 12 configuration classes (tee, cross, manifold, y-tee, parallel-lean, x-form, y-fan-stem, y-piece, capped, mixed-genders, asymmetric-arms).
* New: gallery-archetypes-cut is the cutaway companion.
* Removed: gallery-genders-ends and gallery-genders-ends-cut variants and their modules.
* Y-piece archetype uses left_end = "point" per catalogue convention.
* Ordinal-suffix convention reserved for future archetype sets larger than 12 cells.

See the 0.47.0 ResearchJournal entry for the matrix-vs-archetype
decision, the cell selection rationale, and the catalogue-vs-
symmetry separation.

Version 0.46.0 (2026-05-25)
===========================

* Reducer eccentric parameter takes BOSL2 directional constants.
* CENTER (default), LEFT, RIGHT, FRONT, BACK replace "none", "-x", "+x", "-y", "+y".
* UP and DOWN remain rejected.
* Breaking change: pre-0.46.0 string forms no longer accepted.
* Test-area examples and dispatch variant updated.

See the 0.46.0 ResearchJournal entry for the three-way option
discussion (string vs vector vs directional constants) and the
lesson on checking library idioms when deciding API form.

Version 0.45.0 (2026-05-25)
===========================

* First combinatorial gallery: Manifold gender x end-treatment matrix.
* Two new Manifold gallery modules: solid and cutaway companions.
* Two new dispatch variants: gallery-genders-ends, gallery-genders-ends-cut.
* Default 3/4 view; 12 cells in a 4 (gender) x 3 (end) grid.
* "Point" rows switch to Y-piece form so the point semantics get exercised.
* Combinatorial-render-coverage TODO partially closed; proof of concept.
* Other models (Reducer, Cap, Plug, HexBush, Union, HoseTail, Elbow) pending.
* Taxonomy.org integration pending (separate iteration).

See the 0.45.0 ResearchJournal entry for the design decisions
(why galleries, why 2D grids, why 3/4 view), the rejected
options, and what remains for the broader rollout.

Version 0.44.0 (2026-05-25)
===========================

* Manifold parameter renames: left/right for run ends, top/bottom unchanged for branches.
* end_minus_x renamed to left_end; end_plus_x renamed to right_end.
* gender_run_minus_x renamed to left_gender_run; gender_run_plus_x renamed to right_gender_run.
* Internal _manifold parameters and locals renamed for consistency.
* Breaking change: pre-0.44.0 callers must update parameter names.
* New DevelopmentStandard subsection documents the reference frame and front view.
* Reducer test area gains four eccentric examples (no API change).
* Y-piece junction rounding investigated, decision: defer (low priority, explicit trigger).

See the 0.44.0 ResearchJournal entry for the full rename table,
the front-view convention, and the rounding exploration analysis.

Version 0.43.0 (2026-05-21)
===========================

* G-05 Reducer gains the eccentric subtype.
* New parameter: eccentric, accepting "none" (default), "+x", "-x", "+y", "-y".
* "+z" and "-z" rejected --- they would not produce an eccentric form.
* Offset amount fixed at (arm_od_large - arm_od_small) / 2 (tangent on the named side).
* Concentric default unchanged; pre-0.43.0 callers byte-identical.
* Transition built via BOSL2 hull() of two end discs for the eccentric case.
* hex_ports remains fully orthogonal with eccentric.
* New dispatch variant: eccentric (uses "-x").

See the 0.43.0 ResearchJournal entry for the three design
decisions (string axis vs vector, hull vs skin, hex
orthogonality) and the deferred ASME cross-check.

Version 0.42.0 (2026-05-21)
===========================

* Per-side run-end genders: gender_run_minus_x, gender_run_plus_x.
* Per-side branch genders: top_gender_branch, bottom_gender_branch.
* Scalar gender_run and gender_branch still work as shorthand.
* G-03 Tee and G-04 Cross files removed (deprecated since 0.36.0).
* Manifold subsumes both --- no functional loss.
* New dispatch variant: mixed-genders.
* Junction-fillets TODO re-tagged low-priority, explicit-trigger only.

See the 0.42.0 ResearchJournal entry for the per-side gender API
options, the deletion bookkeeping, and the Manifold parameter
convention now stable across three iterations.

Version 0.41.1 (2026-05-21)
===========================

* Bug fix: bottom-branch male threads no longer float past the tip.
* Manual-experiments comment block rewritten: example reads as a commented scad statement.
* First fix-only iteration: third digit incremented per the new convention.

See the 0.41.1 ResearchJournal entry for the mirror-of-0.41.0
analysis and the versioning convention discussion.

Version 0.41.0 (2026-05-21)
===========================

* Bug fix: bottom-branch female sockets are now cut.
* Mask was placed outside the body via orient=DOWN; removed.
* Male threads on the bottom unaffected; their direction matched outward extension.
* Comment punctuation tidied near the manual-experiments block.

See the 0.41.0 ResearchJournal entry for the why and the
why-it-shipped-twice disclosure.

Version 0.40.0 (2026-05-21)
===========================

* Bug fix: branch body cylinder now penetrates the stem to the pivot.
* Visible gap between branches and stem at non-zero tilt is closed.
* Run-as-point Y-piece geometry now coherent (was partial in 0.39.0).
* No API change; 0.39.0 visible arm-length convention preserved.

See the 0.40.0 ResearchJournal entry for the one-line fix, the
side effect on run-as-point, and the closure of the 0.39.0
"partial" disclosure.

Version 0.39.0 (2026-05-21)
===========================

* /Side/ now means top (+Z) versus bottom (-Z), split by XY plane.
* Per-side branch angle: top_branch_angle, bottom_branch_angle.
* Scalar branch_angle still works as a shorthand for both sides.
* List form branch_angle = [a_left, a_right] removed.
* Per-side arm length: top_arm_length_branch, bottom_arm_length_branch.
* Branch arm length measured from stem cylinder surface, not run axis.
* Minimum arm length enforced: thread_len_branch + 2 * BSPPFIT_MIN_WALL.
* end_minus_x and end_plus_x accept "point" --- run-as-point form, partial.
* Dispatch dropped: y-fan, y-fan-3 (used the dead list form).
* Dispatch added: y-fan-stem, y-fan-point, parallel-lean, x-form.
* 0.37.0/0.38.0 X-shape disclosure corrected: both-sides scalar tilt was always parallel.

See the 0.39.0 ResearchJournal entry for the side redefinition,
the per-side API options considered, and the partial nature of
y-fan-point.

Version 0.38.0 (2026-05-21)
===========================

Symmetric Y-fan landed on the unified Manifold (run-with-stem
form). branch_angle now accepts a two-element list
[a_left, a_right] in addition to the existing scalar: branches
at pX < 0 lean by a_left, at pX > 0 by a_right, at pX = 0
stay perpendicular. Two new dispatch variants: y-fan
(2 branches, [135, 45]) and y-fan-3 (3 branches, [120, 60]).

The same iteration fixes the trunk encroachment on the run
thread for any non-orthogonal branch (the bug visible at
0.37.0 in y-tee at 45 deg and similar). The run end on the
leaning side now extends by the actual X-reach of the tilted
trunk inside the body --- a Pythagoras of arm_od_branch and
arm_od_run by the tilt angle.

The run-as-point Y-fan (three ports meeting at a hollow
junction, no straight pipe) is NOT covered; see the new
Manifold --- run-as-point Y-fan TODO in FutureResearch.

Documentation: BOSL2 version pinning landed in
DevelopmentStandard.org as a prose subsection citing
PR #1877, merge commit ed3afe3, and BOSL_VERSION >=
[2, 0, 716] --- the runtime assert option was considered
and declined. The FutureResearch entry's [2, 0, 739] was
corrected to [2, 0, 716] on PR-author evidence; the
previous value was the working-copy build counter, not
the lower bound.

See the 0.38.0 ResearchJournal entry for rationale,
the options considered for the per-side API, the
Pythagoras derivation, and disclosures (notably: the
combination branch_sides = "both" with a list branch_angle
is not rendered in detail).

Version 0.37.0 (2026-05-20)
===========================

Y-form (non-orthogonal) branches landed on the unified
Manifold: branch_angle accepts 30..150 degrees (90
perpendicular, the existing behaviour, byte-identical). All
branches lean by the same angle (uniform tilt). New y-tee
dispatch variant. The symmetric Y-fan form (branches
splaying apart from a common stem) is NOT covered; see the
new Manifold --- symmetric Y-fan TODO in FutureResearch.

See the 0.37.0 ResearchJournal entry for rationale and
disclosures (notably: branch_sides = "both" with a tilt
produces an X-shape, not parallel branches).

Version 0.36.0 (2026-05-20)
===========================

Three strands:

* Cutaway examples added to each model's test area (as
  commented experiments, the same style as other test-area
  entries).

* Eccentric-vs-concentric reducer explained in a new
  Doc/FutureResearch.org entry; not modelled.

* Branch-fitting taxonomy --- Option B resolved. Tee, Cross
  and Manifold are unified under the single G-10 Manifold
  class. The trade categories survive as configurations:
  Manifold(branch_count=1) is a tee, Manifold(branch_count=1,
  branch_sides="both") is a cross. The G-03 Tee and G-04
  Cross model files are flagged DEPRECATED with a banner
  pointing to the unified Manifold; they remain callable.

Forward provision: branch_angle parameter reserved on the
unified Manifold for the planned Y-form (non-orthogonal)
branches; currently accepts 90 only.

Late additions: BOSL2 BSPP exact-tag verification recorded
in FutureResearch (BOSL_VERSION >= [2,0,739], commit
ed3afe3 or later); a standalone Y-form Manifold TODO
surfaced from the forward provision.

See the 0.36.0 ResearchJournal entry for rationale and the
OBSOLETE list of files becoming candidates for deletion.

Version 0.35.0 (2026-05-20)
===========================

Documentation-only. The branch-fitting taxonomy review (the
standing TODO on tee/cross/manifold coherence and Y-form
manifolds) was started: evidence digested, structural
options laid out, assistant's recommendation recorded in
Doc/FutureResearch.org. No code or taxonomy change ---
decision pending. See the 0.35.0 ResearchJournal entry for
context.

Version 0.34.0 (2026-05-20)
===========================

G-09 HoseTail: the "christmas_tree" barb profile is reworked
to give pronounced sharp ridges with the classic stepped-cone
silhouette. The parameter API is unchanged. A caller
rendering "christmas_tree" gets a visibly different output
from 0.33.0. See the 0.34.0 ResearchJournal entry for
rationale.

Version 0.33.0 (2026-05-19)
===========================

G-05 Reducer: the body_shape parameter ("round"/"hex") is
replaced by hex_ports ("none"/"large"/"small"/"both"), which
places a wrench-grip hex on either body, both, or neither.
The legacy "round" and "hex" values are still accepted. See
the 0.33.0 ResearchJournal entry for rationale.

Version 0.32.0 (2026-05-19)
===========================

Cutaway facility: every model gains a "cutaway" parameter
("none" default, or left/right/front/back/bottom/top) that
applies a planar half-cut for viewing internals. A viewing
aid; "none" leaves all output unchanged. See the 0.32.0
ResearchJournal entry for rationale.

Version 0.31.0 (2026-05-19)
===========================

A new geometry class: G-10 Manifold, the tenth model of the
library.

Project-author timestamp: [2026-05-19 Tue 06:24].

* G-10 Manifold --- BSPP distribution manifold

  Models/G10_Manifold/Manifold.scad is a new model: a straight
  cylindrical run carrying a row of N branch ports, with a port
  at each end of the run. A manifold distributes one supply to
  several take-offs.

  The manifold is pipe-bodied --- the same body family as the
  G-03 Tee and the G-04 Cross. A tee is a pipe run with one
  branch, a cross with two opposed branches, a manifold with N:
  the three lie on a continuum of branch count, recorded in
  Doc/Taxonomy.org. The Manifold is a separate model that reuses
  the Tee's branch-port construction idiom; the Tee and Cross
  are not merged into it.

  Parameters: branch_count (the defining variable); branch_sides
  ("one" or "both" --- branches on one or both sides of the run);
  gender_run and gender_branch (independent per port group);
  end_minus_x and end_plus_x (each run end open or capped);
  size_run, size_branch, branch_pitch and the usual thread,
  arm, and bore controls.

* New render variants and make targets

  The Manifold dispatch module exposes "default", "gallery",
  "both-sides", "female-run", "capped-end" and "six".
  Models/Makefile.am gained the corresponding render targets.

* Documentation

  Doc/Taxonomy.org gains a G-10 entry in the geometry facet,
  recording the pipe-bodied nature and the tee/cross/manifold
  continuum. The Doc/FutureResearch.org manifold entry is marked
  done.

Version 0.30.0 (2026-05-18)
===========================

Documentation-only release. No code change.

Project-author timestamp: [2026-05-18 Mon 20:06].

* Cutaway module recorded for a future iteration

  Doc/FutureResearch.org gained a TODO entry specifying a
  parametric cutaway facility --- a half-cut that reveals a
  model's internals for verification and illustration, built
  on BOSL2's planar-cut modules (half_of, left_half, and the
  rest). The entry works through the design questions: a
  symmetric model needs one static cut, a non-symmetric model
  may need several on different planes; no multiframe renderer
  is needed; the cut target should be a "cutaway" parameter
  defaulting to "none". Implementation is left to its own
  iteration.

Version 0.29.0 (2026-05-18)
===========================

The alternative hose-tail barb profiles --- the last
form-axis variant. With this iteration the form axis is
complete. No new geometry class and no taxonomy change.

Project-author timestamp: [2026-05-18 Mon 20:06].

* Alternative barb profiles

  Models/G09_HoseTail/HoseTail.scad gained a barb_profile
  parameter with three values: "shark_fin" (the default ---
  each barb a single frustum, the profile of every HoseTail
  before 0.29.0), "stepped" (each barb a frustum followed by a
  straight cylindrical land at barb_major_d, a flat seat for
  the hose wall), and "christmas_tree" (the barb diameters
  taper down toward the tip for easy progressive insertion,
  the taper bounded so the tip barb still clears the bore).
  barb_profile is independent of gender and body_shape. All
  pre-0.29.0 HoseTail calls are unchanged.

* New render variants and make targets

  The HoseTail dispatch module gained "stepped" and
  "christmas-tree" variants. Models/Makefile.am gained
  render-HoseTail-stepped and render-HoseTail-christmas-tree
  targets.

* Documentation

  Doc/FutureResearch.org: the hose-tail barb-profiles entry
  marked done. With it the form-axis variant programme is
  complete --- the Reducer and Hose Tail hex bodies, the Hose
  Tail shouldered transition, and now the barb profiles.

Version 0.28.0 (2026-05-18)
===========================

A defect fix and a form-axis variant, both in the G-09 Hose
Tail. No new geometry class and no taxonomy change.

Project-author timestamp: [2026-05-18 Mon 15:04].

* Hose tail default-bore fix

  The HoseTail default through-bore was keyed to the BSPP size
  alone. The bore runs the full length of the fitting and must
  also pass the barb tips (barb_minor_d); when a caller
  overrode barb_minor_d below its size-derived default --- a
  hose tail for a narrow hose --- the size-keyed default bore
  exceeded the barb tip and the bore assertion fired. The
  default is now capped at the same 0.7 proportion taken
  against barb_minor_d. An explicit bore argument is
  unaffected.

* Shouldered body-to-barbs transition

  The HoseTail gained a shoulder_length parameter (default 0).
  At 0 the body abuts the first barb flush, as before --- the
  body must be at least barb_major_d. Above 0 the body may be
  narrower than the barbs and a frustum of that axial length
  steps the body OD up to barb_major_d before the first barb,
  a positive printable step --- the commercial shouldered
  hose-tail form. All pre-0.28.0 HoseTail calls are unchanged.

* New render variants and make targets

  The HoseTail dispatch module gained "hex-female" (a
  hex-bodied female-thread hose tail) and "shouldered"
  variants. Models/Makefile.am gained render-HoseTail-hex-female
  and render-HoseTail-shouldered targets.

* Documentation

  Doc/FutureResearch.org records two project-author research
  items for a later iteration: making the Reducer hex
  per-port parametric (which port carries the hex), after a
  catalogue hunt found no real two-hex reducer; and a
  taxonomy review of manifold fittings, with the question of
  whether tees and crosses are degenerate manifolds.

Version 0.27.0 (2026-05-18)
===========================

The hexagonal-body hose tail --- the form-axis sibling of the
0.26.0 hex-bodied reducer. No new geometry class and no
taxonomy change.

Project-author timestamp: [2026-05-18 Mon 11:02].

* Hexagonal-body hose tail

  Models/G09_HoseTail/HoseTail.scad gained a body_shape
  parameter: "round" (the default --- a circular cylinder,
  every HoseTail before 0.27.0) or "hex" (a regular hexagonal
  prism for the plain body section, a wrench-grip surface).
  The parameter follows the precedent of the Reducer's
  body_shape and the Nipple's middle_shape. The hose tail has
  a single body section, so a hex body is a single
  wrench-grip hex. The threaded end and the barbed cone stack
  are unaffected; body_shape is independent of gender. All
  pre-0.27.0 HoseTail calls are unchanged.

* New render variant and make target

  The HoseTail dispatch module gained a "hex" variant.
  Models/Makefile.am gained a render-HoseTail-hex target.

* Documentation

  Doc/FutureResearch.org: the Reducer hexagonal-body entry
  marked done, with a recorded open question --- the 0.26.0
  reducer makes both body sections hexagonal, an unusual
  trade form; commercial hex reducers more often have a
  single wrench-grip band. The question is noted for future
  exploration pending commercial reference.

Version 0.26.0 (2026-05-18)
===========================

The first form-axis variant: the hexagonal-body reducer. A
FutureResearch note on combinatorial render coverage records
a verification-method point. No new geometry class and no
taxonomy change.

Project-author timestamp: [2026-05-18 Mon 10:33].

* Hexagonal-body reducer

  Models/G05_Reducer/Reducer.scad gained a body_shape
  parameter: "round" (the default --- circular cylinders,
  every Reducer before 0.26.0) or "hex" (regular hexagonal
  prisms providing a wrench-grip body). The parameter follows
  the precedent of the G-01 Nipple's middle_shape parameter.
  Both plain body sections become hexagonal; the conical
  transition frustum between them stays round, since the
  wrench grip is on the straight body sections. body_shape is
  independent of the gender parameters --- a hex body
  combines with any gender combination. All pre-0.26.0
  Reducer calls are unchanged.

* New render variant and make target

  The Reducer dispatch module gained a "hex" variant.
  Models/Makefile.am gained a render-Reducer-hex target.

* Documentation

  Doc/FutureResearch.org: a new TODO entry, "Combinatorial
  render coverage for multi-variant models", records the
  verification-method point raised after the 0.24.0/0.25.0
  hex bush defect --- that a cutaway is a necessary but not
  sufficient correctness check, and that rendering a model's
  full variant matrix may be needed. The entry is a note, not
  a committed task.

Version 0.25.0 (2026-05-18)
===========================

A defect fix: the through-bore of the gender-swapped hex
bush was sized to the wrong port, hollowing the small male
thread into a bare floating helix. No new geometry class and
no new variant.

Project-author timestamp: [2026-05-18 Mon 09:58].

* Hex bush through-bore sizing fix

  Models/G08_HexBush/HexBush.scad now sizes the through-bore
  to the SMALLER of the two ports, whichever gender it
  carries. The 0.24.0 model keyed the bore default and the
  bore validation to size_female, on the assumption that the
  female port is the smaller one --- true for the classic
  large-male/small-female layout, false for the
  gender-swapped large-female/small-male layout. In the
  swapped layout the bore, sized for the large female port,
  was wider than the small male thread's minor diameter and
  removed the thread's core, leaving a bare helical ridge
  with no solid rod beneath it.

  This is a defect fix: a gender-swapped or step-up hex bush
  built with the 0.24.0 release has a hollow male thread and
  should be re-generated. A classic-layout hex bush is
  unaffected --- in that layout the smaller port is the
  female one and the bore sizing is identical to before.

Version 0.24.0 (2026-05-17)
===========================

The gender-swapped hex bush, which completes the gender-axis
variant programme. The same change fixes a latent hex-sizing
defect present since iteration 0.9.7. No new geometry class
and no taxonomy change.

Project-author timestamp: [2026-05-17 Sun 20:31].

* Gender-swapped hex bush, and a hex-sizing fix

  The G-08 Hex Bush is an opposite-gender reducing fitting.
  The classic layout has the larger port male and the
  smaller port female; the gender-swapped layout has the
  larger port female and the smaller port male. Both are
  normal catalogue fittings, selected through the existing
  size_male and size_female parameters (whichever is larger
  determines the layout).

  Models/G08_HexBush/HexBush.scad now sizes the hex body to
  the LARGER of the two ports, whichever gender it carries.
  The 0.9.7 model keyed the hex outer diameter and the
  wall-thickness enforcement to size_male alone, which was
  correct only while the male port was the larger; a
  gender-swapped (large-female) hex bush built that way had
  a hex too small to contain its own female thread cavity.
  This is a defect fix: a gender-swapped or step-up hex bush
  built with a pre-0.24.0 release should be re-generated.

  A new assert requires the hex across-flats to clear the
  female thread cavity with a wall remaining. The misleading
  "step-up adapter, atypical" warning is replaced with a
  neutral echo that flags only the genuinely unusual
  equal-size case.

* New render variant and make target

  The HexBush dispatch module gained a "swapped" variant.
  Models/Makefile.am gained a render-HexBush-swapped target.

* Documentation

  Doc/FutureResearch.org: the per-port variant space entry
  records the gender axis as complete for every model class
  that admits a gender choice, and explains why the hex
  bush's gender options are a which-port-is-which choice
  rather than the four-way per-port space.

Version 0.23.0 (2026-05-17)
===========================

The gender variants of the G-07 Union --- the most
structurally involved fitting in the library, a three-piece
assembly. With this iteration the gender axis is complete
for the Reducer, the hose tail, and the union. No new
geometry class and no taxonomy change.

Project-author timestamp: [2026-05-17 Sun 20:15].

* Union female-port and mixed-gender variants

  Models/G07_Union/Union.scad gained per-pipe-end gender.
  The Union wrapper takes gender_a and gender_b, one for
  each pipe-connection end; the piece modules union_tail_a
  and union_tail_b each take a gender parameter. The two
  ends are independent, so the Union now produces all four
  gender combinations: M x M (the default, joins two
  female-threaded pipes), M x F and F x M (mixed), and F x F
  (joins two male-threaded pipes). Every gender parameter
  defaults to "M" --- all pre-0.23.0 Union calls are
  unchanged.

  A female pipe end carries a tapped socket: the tail's
  plain body section is extended to cover the pipe-thread
  region as solid stock and an internal bspp_threaded_rod is
  subtracted from it, the Cap.scad idiom. The nut-to-collar
  coupling thread --- internal to the union mechanism, not a
  pipe-connection end --- is unaffected by the pipe-end
  gender.

* New render variants and make targets

  The Union dispatch module gained "mxf" and "fxf" variants.
  Models/Makefile.am gained render-Union-mxf and
  render-Union-fxf targets.

* Documentation

  Doc/FutureResearch.org: the Union female-port and
  mixed-gender variants queue entry marked resolved; the
  per-port variant space entry records the Union gender axis
  as fully covered.

Version 0.22.0 (2026-05-17)
===========================

The third gender-axis variant: the female-thread hose tail.
An autotools fix lets the project configure and build
without Emacs (needed only for the documentation targets).
No new geometry class and no taxonomy change.

Project-author timestamp: [2026-05-17 Sun 15:41].

* Female-thread hose tail

  Models/G09_HoseTail/HoseTail.scad gained a gender
  parameter. With gender = "M" (the default) the threaded
  end is male, exactly as before --- the tail screws into a
  female port. With gender = "F" the threaded end is a
  tapped socket and the tail screws onto a male pipe stub.
  The barbed end is unaffected. The female thread uses the
  Cap.scad idiom. All pre-0.22.0 HoseTail calls are
  unchanged.

* Build no longer requires Emacs except for documentation

  configure.ac now treats GNU Emacs as a soft dependency: a
  missing or too-old Emacs produces a warning, not a fatal
  error, and ./configure proceeds. Emacs is used only by
  the "make pdf" and "make html" documentation targets,
  which now fail with a clear message if invoked without
  it. Building the programs and running the model-rendering
  targets no longer require Emacs at all.

* New render variant and make target

  The HoseTail dispatch module gained a "female" variant.
  Models/Makefile.am gained a render-HoseTail-female
  target.

* Documentation

  Doc/FutureResearch.org: the female-thread hose tail queue
  entry marked resolved; the per-port variant space entry
  records the hose tail's gender axis.

Version 0.21.0 (2026-05-17)
===========================

The second gender-axis variant: the Reducer FxF female
reducer, completing the G-05 Reducer gender axis. A
taxonomy-document structural repair rounds out the
iteration. No new geometry class and no taxonomy-coverage
change.

Project-author timestamp: [2026-05-17 Sun 15:13].

* Reducer FxF female reducer

  Models/G05_Reducer/Reducer.scad gained a gender_large
  parameter mirroring the gender_small added at 0.20.0. The
  two are independent, so the Reducer now produces all four
  gender combinations: M x M (the plain reducer, the
  default), M x F (the reducing bushing), F x F (the female
  reducer), and F x M (the reverse bushing). Both gender
  parameters default to "M" --- all pre-0.20.0 Reducer
  calls are unchanged. A female port becomes a tapped
  socket by the Cap.scad idiom.

* New render variant and make target

  The Reducer dispatch module gained an "fxf" variant.
  Models/Makefile.am gained a render-Reducer-fxf target.

* Taxonomy Glossary repair

  Doc/Taxonomy.org: the "* Glossary" heading, its anchor,
  and the opening of its description --- lost when the
  Facet Audit section was inserted at iteration 0.17.0 ---
  are restored. The Glossary is again a top-level section
  with its subsections correctly nested; a dangling
  glossary cross-reference in Doc/DevelopmentStandard.org
  now resolves.

* Documentation

  Doc/FutureResearch.org: the Reducer FxF queue entry
  marked resolved; the per-port variant space entry records
  the Reducer gender axis as fully covered.

Version 0.20.0 (2026-05-17)
===========================

The first gender-axis variant: the Reducer reducing bushing.
A render-help discoverability fix and verification of the
development OpenSCAD round out the iteration. No new geometry
class and no taxonomy change.

Project-author timestamp: [2026-05-17 Sun 11:11].

* Reducer reducing bushing (M large x F small)

  Models/G05_Reducer/Reducer.scad gained a gender_small
  parameter. With gender_small = "M" (the default) both
  ports are male, exactly as before --- all pre-0.20.0
  Reducer calls are unchanged. With gender_small = "F" the
  small port becomes a tapped female socket and the fitting
  is a reducing bushing: the large male end screws into a
  female-port fitting, the small female end accepts a
  male-threaded pipe. The female socket is produced by the
  same idiom as Cap.scad --- an internal bspp_threaded_rod
  subtracted from the solid small body.

* make help lists all coverage modes for variant targets

  The render-variant section of "make help" now prints the
  turntable, hemisphere, and sphere target for each variant,
  each with its frame count. The targets themselves were
  already generated for all three coverage modes since
  0.18.0; only the help listing was incomplete.

* New render variant and make target

  The Reducer dispatch module gained a "bushing" variant.
  Models/Makefile.am gained a render-Reducer-bushing target.

* Documentation

  Doc/DevelopmentStandard.org: a note in the coverage-mode
  guidance confirming the reducing tee and reducing cross
  keep their geometry class's coverage mode.
  Doc/FutureResearch.org: the Reducer reducing-bushing queue
  entry marked resolved.

Version 0.19.0 (2026-05-17)
===========================

The first two reducing fittings: the reducing tee and the
reducing cross. No new geometry class and no taxonomy
change. Each branching fitting gains an independent
branch-port size --- the first moves into the per-port
variant space along its size axis.

Project-author timestamp: [2026-05-17 Sun 10:04].

* Reducing tee

  Models/G03_Tee/Tee.scad gained a size_branch parameter:
  the branch port C may take a BSPP size different from the
  run ports A and B. The common commercial case is a branch
  smaller than the run (G1/2 x G1/2 x G1/4). The companion
  parameters thread_length_branch, arm_length_branch,
  arm_od_branch, and bore_branch let every branch dimension
  be set independently; each defaults to a size_branch-
  derived value. With size_branch left unset the fitting is
  an equal tee, exactly as before --- all pre-0.19.0 calls
  are unchanged.

* Reducing cross

  Models/G04_Cross/Cross.scad gained the same parameter set.
  The cross reduces as a pair: the run ports A and B (X
  axis) keep size; the branch ports C and D (Z axis) both
  take size_branch.

* Branch arm-OD clamp

  Both fittings clamp the branch arm outer diameter not to
  exceed the run arm outer diameter, so a branch larger than
  the run --- the unusual case --- still produces a sound
  body junction.

* Render variants and make targets

  The Tee and Cross dispatch modules gained a "reducing"
  variant. Models/Makefile.am gained render-Tee-reducing and
  render-Cross-reducing targets.

* Documentation

  Doc/Taxonomy.org: the G-04 Cross entry in the Geometry
  Facet enumeration now links to its glossary term, matching
  its sibling entries. Doc/FutureResearch.org: the reducing
  tee and reducing cross queue entries are marked resolved.

Version 0.18.0 (2026-05-16)
===========================

An infrastructure iteration. No new model and no taxonomy
change. It gives the render pipeline the ability to target a
named variation of a model --- the Union's exploded view in
particular --- closing a residual item from iteration 0.17.0.

Project-author timestamp: [2026-05-16 Sat 19:54].

* Render-dispatch module in every model file

  Each of the ten model files now carries a render-dispatch
  module named <Model>_Render and a top-level "render" string
  knob. The dispatch module maps a variant name to the module
  call that produces it; the file's active top-level statement
  is a single call to that dispatch module. Opened in the
  OpenSCAD GUI with no -D option the file shows its default
  view, exactly as before. Every model recognises "default"
  and "gallery"; the Union additionally recognises "exploded"
  and the three single-piece variants "tail-a", "tail-b",
  "nut".

* New render-pipeline option: --render-variant

  bin/render-views accepts --render-variant NAME. The name is
  passed to OpenSCAD as -D render="NAME", which selects the
  dispatch branch for that variant. With no --render-variant
  the script behaves exactly as before 0.18.0.

* New make targets: render-<Model>-<variant>

  Models/Makefile.am generates a render-<Model>-<variant>
  target (with -hemisphere / -sphere coverage suffixes) for
  each entry of its RENDER_VARIANTS list. A variant render's
  PNGs, tar, and MP4 carry the <Model>-<variant> filename stem
  so they do not overwrite the default render's output.
  "make help" lists the variant targets.

* New helper: bsppfit_is_variant

  Models/Util/util.scad gained bsppfit_is_variant(name,
  variants), the whole-string membership test the dispatch
  modules use to validate a requested variant.

* Documentation

  Doc/DevelopmentStandard.org gained the sections Render
  Dispatch Module and Render Variant Selection.
  Models/LibraryOverview.org records the render-dispatch
  convention. Doc/man/render-views.1 documents
  --render-variant. The iteration-0.17.0 residual item in
  Doc/FutureResearch.org --- the render pipeline could not
  target the exploded view automatically --- is marked
  resolved.

Version 0.17.1 (2026-05-16)
===========================

A patch iteration. No model or taxonomy change. It hardens
project continuity across working-session boundaries and
records two corrections of assistant errors. Triggered by
the project author hitting the per-conversation
uploaded-file limit and asking what must be provided to
resume the project in a new session without loss of state.

Project-author timestamp: [2026-05-16 Sat 15:19].

* New document: Doc/Resuming.org

  States, durably and inside the delivery archive, how to
  continue BSPPFit in a new working session with no loss of
  state. Covers the two essential uploads (the BOSL2 library
  archive BOSL2-master.zip, and the latest BSPPFit-X.Y.Z
  delivery archive), the recommended transcript uploads, the
  principle that the delivery archive is self-describing,
  and start-of-session and end-of-session checklists. Built
  to PDF and HTML like every other project document.

* New archive artifact: Doc/transcript-catalog.txt

  The assistant environment maintains a catalogue of
  past-session transcript summaries. That catalogue is not a
  project file and a new session may not have it; a copy is
  now distributed inside the delivery archive so its
  information survives regardless.

* Correction: where bspp_threaded_rod is defined

  During iterations 0.15.0--0.17.0 the assistant's working
  notes wrongly recorded that bspp_threaded_rod was not a
  BOSL2 module and speculated it came from a fork. It is
  defined in BOSL2's threading.scad (a function + module
  pair) and takes a fractional-inch size looked up in
  BOSL2's bspp_dimensions table. The util.scad comment
  describing it as "BOSL2's bspp_threaded_rod()" was correct
  all along. The 0.17.0 Union code is correct against the
  real signature; no .scad file changed. The error was in
  the assistant's notes only, caused by searching a guessed
  subset of BOSL2 files rather than the whole tree.

* Correction: the BSPP size range and the G2 coupling-size clamp

  Iteration 0.17.0 said a G2 union has no wider BSPP size
  for its coupling thread, implying an inherent ceiling at
  G2. The accurate account, now in FutureResearch.org: ISO
  228-1 defines sizes well beyond G2; the project's own
  table is deliberately restricted to G1/8..G2 (a scope
  choice); and BOSL2's bspp_dimensions table runs 1/16..2
  and stops there. The operative ceiling for a renderable
  thread is BOSL2's table, not the project's choice or the
  standard.

* Honest disclosures

  - No model or build change was needed for the
    bspp_threaded_rod matter; only the assistant's notes
    were wrong. This is a documentation-and-process
    iteration.
  - Doc/transcript-catalog.txt is a point-in-time copy,
    refreshed only in iterations with access to the live
    catalogue. The source of truth for project history
    remains ResearchJournal.org.
  - The continuity guarantee in Resuming.org depends on the
    journal discipline being followed each iteration; it is
    a discipline, not an automatic property.

* Phase 1 status

  Weighted Phase 1 aggregate: roughly 95.2%, unchanged. A
  patch iteration; no coverage change.


Version 0.17.0 (2026-05-16)
===========================

A minor iteration with two strands: Union refinements
prompted by detailed project-author feedback, and the
§24.3.4 facet audit against ISO 12006-2 and UniClass 2015.
No new geometry class; the headline Phase 1 aggregate is
unchanged. The value of the iteration is taxonomic
confidence (the facet audit) and one model corrected to
commercial fidelity (the Union coupling thread).

Project-author timestamp: [2026-05-16 Sat 14:46].

* Union: BSPP coupling thread

  The 0.16.0 Union used a generic 1.5 mm-pitch vee thread
  for the nut-to-collar coupling joint, a value the 0.16.0
  honest disclosures had flagged as not sourced from a
  standard. The project author supplied a PVC-Welt
  catalogue description of a brass coupling union
  confirming that the union ring nut's thread is a BSP pipe
  thread per ISO 228-1.

  The 0.17.0 Union models the coupling thread as a real
  BSPP thread: bspp_threaded_rod for tail A's external
  collar thread, bspp_threaded_rod(internal = true) for the
  ring nut's internal thread. The coupling thread is now
  the same thread form as the union's pipe threads.

* Union: coupling_size parameter

  A new parameter on union_tail_a, union_tail_b, union_nut,
  and the Union wrapper. It is the BSPP size of the
  coupling thread, settable independently of the union's
  pipe size for heterogeneous piping. Default: the smallest
  BSPP catalogue size whose major diameter clears the plain
  body OD (for a G1/2 union, this is G3/4 --- the coupling
  thread must be wider than the body, which surrounds the
  bore and the pipe-thread body).

  Edge case: for a G2 union no standard BSPP size is wider
  than the body, so the default coupling size clamps to G2.

* Union: Union_Exploded module

  A dedicated module rendering the union in its exploded
  pose (the three pieces separated along the axis), with a
  size-proportional default gap. Added in response to the
  project author's observation that the exploded rendering
  needs a module of its own rather than hand-placed piece
  calls. Note: the render pipeline still renders a .scad
  file's top-level statement, so a make render-Union-
  exploded target remains a queued render-pipeline
  enhancement.

* Facet audit against ISO 12006-2 and UniClass 2015

  New section "Facet Audit against ISO 12006-2 and UniClass
  2015" in Doc/Taxonomy.org. The empirically-chosen facets
  F-01 through F-08 are audited against the
  faceted-classification discipline of ISO 12006-2 (the
  meta-framework) and UniClass 2015 (its eleven-table
  realisation).

  Result: the facets are sound --- no renumbering, no facet
  removal. Seven clarifications, of which the most
  consequential are:
    - BSPPFit is a deep single-product-class taxonomy; its
      facets are properties inside UniClass Products (Pr),
      not table-level peers of UniClass's eleven tables.
    - F-02 Gender, F-03 Thread form, F-04 Nominal size are
      per-port facets, indexed against a port schema that
      F-01 Geometry fixes. This names the project's
      combinatorial variant space precisely.
    - F-07 Pressure / temperature rating is a derived
      property, not a free facet.
    - Activities and Tools are deliberately not adopted as
      facets; hierarchical coding is not adopted at the
      current scale.

* Illustration pass deferred

  The project author deferred the illustration pass: the
  taxonomy is not yet fully covered, the modelling is
  consequently not comprehensive, and the domain's high
  combinatorics warrant gaining confidence in the
  taxonomy's diversity first. The facet audit is the step
  taken instead.

* Honest disclosures

  - The Union changes are not render-verified by the
    assistant: the project author's two 0.17.0 Union
    renders did not reach the assistant because of an
    upload-system limitation. First verification is the
    project author's make render-Union on receipt.
  - The default coupling size clamps at G2 (see above).
  - The coupling thread is now standard-form, but the
    collar/nut/lip proportions remain assistant-chosen
    rather than sourced from a dimensioned union drawing.
  - The facet audit read the standards as frameworks (ISO
    12006-2's object classes, UniClass's eleven tables),
    not line by line; its conclusions are structural-level.

* Phase 1 status

  Per-component:
    Descriptive taxonomy        ~99% (facet audit raises
                                 confidence; no material
                                 percentage change)
    Illustrations                ~56% (no change; deferred)
    Per-size dimension tables   100% (unchanged)
    Validation pass             100% (unchanged)
    BSPP 3D model library       100% (coverage unchanged)

  Weighted Phase 1 aggregate: roughly 95.2%, unchanged from
  0.15.0 and 0.16.0. Like 0.16.0, this is a quality and
  confidence iteration rather than a coverage iteration:
  the facet structure is now audited rather than merely
  empirical, and the variant space has an explicit shape.


Version 0.16.0 (2026-05-16)
===========================

A correction iteration. No new geometry class --- all nine
were covered at 0.15.0. Instead, 0.16.0 corrects a
design-philosophy error in the 0.15.0 Union, prompted by a
project-author observation, and records the general
principle behind the correction.

Project-author timestamp: [2026-05-16 Sat 09:25].

* The manufacturing-fidelity principle (DevelopmentStandard.org)

  New subsection opening the OpenSCAD Project Standards
  section: "Models Are For Manufacturing, Not Only
  Rendering".

  The rule: a model must include all functional geometry ---
  threads, bores, clearances, seats, chamfers --- regardless
  of whether that geometry is visible in an assembled
  render. Geometry must never be omitted on "hidden in the
  assembled view" grounds.

  Two corollaries: multi-piece fittings are modelled as
  separate non-fused pieces, each its own manufacturable
  solid; mating pieces carry the print/machine clearance
  ($slop, or explicit diameter clearance) that lets them
  actually assemble.

  The principle was prompted by the project author's
  correction of the 0.15.0 Union, which had omitted the
  internal coupling threads with the (mistaken) rationale
  that they are invisible in the assembled render. The
  models are for 3D printing and other manufacturing, not
  only for catalogue images.

* Union (G-07) rewritten as three manufacturable pieces

  The 0.15.0 Union had two faults, both consequences of an
  "assembled render is all that matters" mindset: the three
  sub-bodies were boolean-fused into one rigid solid (a 3D
  print of which cannot function as a union --- the nut
  cannot turn), and the ring-nut-to-collar coupling threads
  were omitted (without them the nut cannot screw on).

  The 0.16.0 rewrite provides three independent,
  independently-manufacturable modules:
    - union_tail_a : threaded tail. BSPP male pipe thread,
      body, collar with a real EXTERNAL coupling thread.
      Inner face is a 60-degree conical seat recess.
    - union_tail_b : shouldered tail. BSPP male pipe thread,
      body, plain collar shoulder. Inner face is the
      matching 60-degree conical seat protrusion.
    - union_nut : hex ring nut with a real INTERNAL coupling
      thread and an inward retaining lip capturing tail B's
      collar shoulder.

  Each module renders and exports on its own for
  manufacturing. The Union wrapper positions the three in
  the assembled pose for the catalogue view and does NOT
  boolean-fuse them. A new explode parameter (default 0)
  separates the pieces along the axis for an exploded view.

  The 60-degree cone seat (shown in the reference section
  drawing union-droit-male-1-bspp-male-1-bspp.jpg) is
  modelled as a shallow conical frustum land: a recess on
  tail A, a matching protrusion on tail B.

* Honest disclosures

  - No end-to-end render of the rewritten Union in the
    assistant's environment. This iteration carries more
    render-unverified geometry than any since the 0.10.2
    Elbow rewrite; the assembly positioning arithmetic is
    the most likely place for a defect. First test is the
    project author's make render-Union.
  - The coupling thread is a generic 1.5 mm-pitch vee
    thread, not a BSPP thread and not sourced from a
    standard; real union ring-nut threads are
    manufacturer-specific.
  - The cone seat is plain metal-to-metal; the soft-gasket
    (flat-seat) variant is queued in FutureResearch.

* FutureResearch updates

  Marked DONE at 0.16.0: "model the internal coupling
  threads", "exploded / separated view", "cone-seat" (the
  flat-gasket-seat alternative remains queued). New entry
  "Manufacturing-fidelity audit of all models" (DONE):
  only the Union violated the principle; the other nine
  models are single manufacturable solids and comply.

* Phase 1 status

  Per-component:
    Descriptive taxonomy        ~99% (no change)
    Illustrations                ~56% (no change)
    Per-size dimension tables   100% (unchanged)
    Validation pass             100% (unchanged)
    BSPP 3D model library       100% (coverage unchanged)

  Weighted Phase 1 aggregate: roughly 95.2%, unchanged
  from 0.15.0. The headline number measures coverage
  (which geometry classes have a model), and the Union
  already counted. The 0.16.0 work is a quality
  correction: the Union went from a non-manufacturable
  fused solid to three manufacturable pieces. The
  completion metric has no separate model-quality axis;
  the honest summary is that the number is flat but the
  Union is now a real, manufacturable union.


Version 0.15.0 (2026-05-16)
===========================

Minor-version bump. The 0.14.0 HoseTail is verified by
project-author render review. The 0.15.0 minor version adds
the Union (G-07) --- the tenth fitting and the last of the
nine F-01 geometry classes. With the Union delivered, every
geometry class in the BSPPFit taxonomy has at least one
end-to-end parametric model, and the Phase 1 BSP
model-library component reaches 100%.

Project-author timestamp: [2026-05-16 Sat 08:53].

* Union model added (G-07)

  Models/G07_Union/Union.scad is the tenth fitting in the
  library and the last of the nine F-01 geometry classes.
  M x M BSPP pipe union, modelled in its assembled state.

  A pipe union joins two threaded pipes and --- unlike a
  coupling --- can be disconnected later without rotating
  the pipes themselves: a ring nut in the middle is
  loosened and the two halves separate.

  First model with multi-sub-body construction. The Union
  is composed of three independently-defined sub-bodies:
  _union_end_piece (invoked twice --- once directly for
  end piece B, once through zflip() for end piece A) and
  _union_nut. All previous fittings are a single boolean
  assembly.

  Geometric layout: longitudinal axis along Z, seat plane
  (where the two end pieces meet, centre of the ring nut)
  at the origin. Each end piece is thread + body + collar;
  the collar's seat face sits on z = 0. The ring nut is a
  hexagonal prism centred at the origin, surrounding the
  two collars.

  The hidden internal threads (ring-nut-to-collar) are NOT
  modelled: in the assembled state they are entirely
  inside the nut, so modelling them would add geometry
  invisible in any external view. The two BSPP
  pipe-connection threads ARE modelled.

  Parameters: size (default 1/2), thread_length (default
  per bsppfit_useful_thread_length), body_length (default
  6 mm), collar_length (default 5 mm), arm_od (default
  major_od + 4 mm), collar_od (default arm_od + 3 mm),
  nut_af (default collar_od + 6 mm), nut_length (default
  2 * collar_length + 2 mm), bore (default per
  bsppfit_default_bore), manifold_safe (default true),
  tol_thread, anchor/spin/orient.

  Five asserts validate body_length > 0, collar_length >
  0, collar_od > arm_od, nut_af > collar_od, nut_length
  >= 2 * collar_length, and the bore constraints.

  Registered for rendering: make render-Union,
  -hemisphere, -sphere.

* Phase 1 geometry-class coverage complete

  With the Union, all nine F-01 geometry classes (G-01
  Straight through G-09 Hose Tail) have at least one
  end-to-end parametric model:

    G-01 Straight  : Nipple
    G-02 Elbow     : Elbow
    G-03 Tee       : Tee
    G-04 Cross     : Cross
    G-05 Reducer   : Reducer
    G-06 CapPlug   : Cap, Plug
    G-07 Union     : Union     <- added this iteration
    G-08 HexBush   : HexBush
    G-09 HoseTail  : HoseTail

  The Phase 1 BSP-3D-model-library component is at 100%.
  Variant work (reducing tees, hex-body reducers,
  female-thread hose tails, exploded union views, and so
  on) continues in FutureResearch.org, but every geometry
  class is now covered.

* HoseTail (0.14.0) verified

  Project-author rendered the 0.14.0 HoseTail in sphere
  mode and uploaded the tarball at 0.15.0. Assistant
  review confirmed the shark-fin barb direction is
  correct (the orient = DOWN trick worked) and the
  barbed-tip face is clean. The FutureResearch entry is
  updated to VERIFIED at 0.15.0.

* Honest disclosures

  - No end-to-end render of the new Union in the
    assistant's environment. First verification is the
    project-author's make render-Union-sphere on
    receipt.
  - The Union is modelled assembled, not exploded. An
    assembled union resembles a hex-bodied nipple; the
    larger hex ring nut and the collar shoulders are the
    distinguishing cues. An exploded-view variant is
    queued in FutureResearch.
  - The hidden internal threads are deliberately
    omitted (invisible in the assembled state). Queued
    for revisiting if an exploded or cut-away view is
    added.
  - Multi-sub-body construction is new in this model.
    If the render shows a gap or non-manifold warning
    at a sub-body interface, the eps overlaps need
    adjustment.

* Phase 1 status

  Per-component:
    Descriptive taxonomy        ~99% (no change)
    Illustrations                ~56% (no change)
    Per-size dimension tables   100% (unchanged)
    Validation pass             100% (unchanged)
    BSPP 3D model library       100% (up from ~67%)

  Weighted Phase 1 aggregate: roughly 95.2% (up from
  ~83.65% at 0.14.0). The ~11.5 percentage-point
  increment is the largest single-iteration jump in the
  project's history, because the Union completes the
  entire BSPP-3D-model-library component (the component
  went from ~67% to 100% in this one iteration).

  What remains for Phase 1: the Illustrations component
  (~56%) and a residual ~1% of the descriptive
  taxonomy. The model library, the per-size dimension
  tables, and the validation pass are all at 100%.


Version 0.14.0 (2026-05-15)
===========================

Minor-version bump. The 0.13.0 Reducer is verified by
project-author render review, with the project-author's
upload of /both/ turntable and sphere coverage of the
Reducer surfacing an error in the 0.13.0 coverage-mode-
per-symmetry guidance. The 0.14.0 minor version adds the
HoseTail (G-09) --- the ninth fitting in the library and
the first with a barbed cone feature instead of a thread
on one end --- and corrects the coverage-mode guidance.

Project-author timestamp: [2026-05-15 Fri 21:29].

* HoseTail model added (G-09)

  Models/G09_HoseTail/HoseTail.scad is the ninth fitting
  in the library. BSPP male thread on one end, barbed
  cone (Christmas-tree shark-fin) on the other end. The
  barb pattern resists hose pull-off: each barb's wider
  trailing edge digs into the hose's inner wall when
  pulled.

  First model with no thread on one end. Second model
  using BOSL2's cyl(d1=..., d2=..., l=...) frustum form
  (after the 0.13.0 Reducer); first model using a
  stacked-repeating-frustum pattern, with N barbs
  placed by a for-loop. Each barb uses orient = DOWN to
  flip BOSL2's d1-at-bottom convention so the smaller
  leading-edge diameter ends up at the +Z (hose tip)
  side.

  Geometric layout: local origin at the centre of the
  overall length. Thread at the -Z end (opens -Z),
  plain body in the middle, barbs at the +Z end (barbed
  tip at +Z = L/2).

  Parameters: size (default 1/2), thread_length (default
  per bsppfit_useful_thread_length), body_length
  (default 8 mm), barb_count (default 4), barb_pitch
  (default 4 mm), barb_minor_d (default major_od + 1 mm
  = 21.96 mm for G1/2), barb_major_d (default
  barb_minor_d + 2 mm = 23.96 mm), arm_od (default
  max(major_od + 4, barb_major_d) = 24.96 mm), bore
  (default per bsppfit_default_bore), manifold_safe
  (default true), tol_thread (default
  BSPPFIT_TOL_THREAD), anchor/spin/orient.

  Six asserts validate barb_count >= 1, barb_pitch > 0,
  body_length > 0, barb_major_d > barb_minor_d, arm_od
  >= barb_major_d (no negative-step body-to-barbs
  transition), and bore constraints (non-negative, at
  most BSPP minor diameter, at most barb_minor_d).

  Important construction note: barbs butt cleanly with
  NO eps overhang between adjacent barbs. This is
  different from every other body-thread or body-
  frustum interface in the library. Coaxial frustums
  under boolean union take MAX of diameters; a butted
  arrangement produces a clean step at each barb
  boundary, while an overlapped arrangement would
  produce a "lip" past each trailing edge. The
  commentary in the _hose_tail module documents this
  choice explicitly.

  Registered for rendering: make render-HoseTail,
  -hemisphere, -sphere. The HoseTail needs SPHERE
  coverage per the corrected coverage-mode-per-
  symmetry guidance (rotationally symmetric about Z
  but ends differ: threaded port vs barbed tip).

* Coverage-mode-per-symmetry guidance correction

  The 0.13.0 first cut grouped fittings by symmetry
  alone, classifying Nipple, Cap, Plug, HexBush, and
  Reducer all as "rotational about Z = turntable
  suffices". This was wrong for Cap, Plug, HexBush,
  and Reducer because their two ends differ
  (closed/open, head/threaded, M/F, large/small) and
  turntable mode covers only the equator side
  profile, not the end-face geometry.

  The 0.14.0 correction distinguishes /rotational
  symmetry/ from /end-similarity/. Turntable
  suffices only when both criteria are met:

    | Fitting              | Symmetry / end-similarity         | Minimum    |
    |----------------------|-----------------------------------|------------|
    | Nipple (M x M, same) | rot. about Z; ends identical      | turntable  |
    | Cap                  | rot. about Z; ends differ         | sphere     |
    | Plug                 | rot. about Z; ends differ         | sphere     |
    | HexBush              | 6-fold rot. about Z; ends differ  | sphere     |
    | Reducer              | rot. about Z; ends differ         | sphere     |
    | Elbow                | L-shape; no plane of symmetry     | sphere     |
    | Tee                  | T-shape; mirror through XZ only   | sphere     |
    | Cross                | + shape; full symmetry both ways  | hemisphere |

  Only Nipple and Cross are reduced below sphere; the
  rest need sphere coverage. The project-author's
  intuition at 0.14.0 ("IMHO turntable is not
  sufficient for the reducer") triggered this
  correction.

* Reducer (0.13.0) verified

  Project-author rendered the 0.13.0 Reducer in both
  turntable and sphere modes and uploaded both at
  0.14.0. The FutureResearch entry is updated to
  VERIFIED at 0.14.0.

  Bonus: project-author uploaded HTC dimensioned
  drawing MF0205_Zeichnung.jpg showing a hex-bodied
  reducer variant with dimensioned wrench size S_W.
  The existing FutureResearch entry for the Reducer
  hex-body variant is strengthened with this direct
  commercial reference.

* Honest disclosures

  - No end-to-end render of the new HoseTail in the
    assistant's environment.
  - The barb orient = DOWN trick is new in this
    model. If the first project-author render shows
    barbs pointing the wrong way (small-end on the
    thread side instead of on the tip side), the
    orient should be flipped to UP.
  - Barbs butt with no eps overhang BY DESIGN; this
    is different from every other interface in the
    library. The reason is documented in the
    _hose_tail commentary.
  - The 0.13.0 coverage-mode misclassification was a
    real error. The 0.14.0 correction adds the
    end-similarity criterion that was missing.

* Phase 1 status

  Per-component:
    Descriptive taxonomy        ~99% (no change)
    Illustrations                ~56% (no change)
    Per-size dimension tables   100% (unchanged)
    Validation pass             100% (unchanged)
    BSPP 3D model library       ~67% (up from ~56%)

  Weighted Phase 1 aggregate: roughly 83.65% (up
  from ~79.8% at 0.13.0). The ~3.85 percentage-
  point increment is larger than recent increments
  because the HoseTail introduces a new
  construction idiom (stacked-frustum loop) AND
  the "no thread on one end" pattern AND completes
  the next-to-last geometry class. Only the Union
  (G-07) remains in Phase 1's geometry-class
  coverage.


Version 0.13.0 (2026-05-15)
===========================

Minor-version bump. The 0.12.x line closed with the Cross
(G-04) added and verified by project-author render review.
The 0.13.0 minor version opens by adding the Reducer (G-05)
--- the first fitting in the library with /per-port size
variation/ --- and by formalising the symmetry-driven
coverage-mode guidance that project-author's
hemisphere-vs-sphere question at this iteration surfaced.

Project-author timestamp: [2026-05-15 Fri 21:00].

* Reducer model added (G-05)

  Models/G05_Reducer/Reducer.scad is the eighth fitting in
  the library. M x M BSPP reducer: two threaded ports of
  /different/ nominal sizes connected by a tapered conical
  transition section. First model with per-port size
  variation; first model using BOSL2's cyl(d1=..., d2=...)
  frustum form.

  Geometric layout: longitudinal axis along Z, large port
  at z = -arm_length_large (opens -Z), small port at z =
  +arm_length_small (opens +Z), transition frustum centred
  at the origin spanning z in [-transition_length/2,
  +transition_length/2]. Between the frustum and each
  thread is a plain cylindrical body section. Bore is
  stepped: large bore on the large side, small bore on
  the small side, conical bore transition mirroring the
  outer frustum.

  Parameters with _large / _small suffixes: size_large
  (default 1/2), size_small (default 3/8), thread_length_*,
  arm_length_*, arm_od_*, bore_*. New transition_length
  parameter defaulting to 5 mm. Asserts validate the
  size ordering, the arm-frustum-thread non-overlap, the
  transition positivity, and the bore ordering / minor-od
  containment.

  Registered for rendering: make render-Reducer,
  -hemisphere, -sphere. The Reducer is rotationally
  symmetric about Z so turntable mode is sufficient per
  the new coverage-mode-per-symmetry guidance.

* Coverage-mode-per-symmetry guidance (DevelopmentStandard.org)

  New sub-section under § Model Rendering Pipeline /
  Coverage modes. Codifies the project-author-driven
  guidance from this iteration:

    | Fitting           | Symmetry                          | Min cov.   |
    |-------------------|-----------------------------------|------------|
    | Nipple, Cap, Plug | rotational about Z                | turntable  |
    | HexBush           | 6-fold rotational about Z         | turntable  |
    | Elbow             | L-shape; no plane of symmetry     | sphere     |
    | Tee               | T-shape; mirror through XZ only   | sphere     |
    | Cross             | + shape; mirror both X and Z      | hemisphere |
    | Reducer           | rotational about Z                | turntable  |

  Upload protocol: project author sends the minimum
  coverage. Sending more wastes tarball size and render
  time without adding information.

  The guidance is project-author-driven (Peter asked at
  0.13.0 whether hemisphere was sufficient for the
  Cross) but formalises a pattern that has been
  implicit since the render pipeline was introduced at
  0.10.0.

* Cross (0.12.0) verified

  Project-author rendered the 0.12.0 Cross in hemisphere
  mode and uploaded the resulting 109-frame tarball at
  0.13.0. Project-author verdict: "seem correct for this
  phase". The FutureResearch entry for the 0.12.0 Cross
  is updated to VERIFIED at 0.13.0.

* Honest disclosures

  - No end-to-end render of the new Reducer in the
    assistant's environment. The Reducer was authored
    using the BOSL2 source as reference for the
    cyl(d1=..., d2=..., l=...) frustum syntax (verified
    against shapes3d.scad:2518).
  - First model using cyl-as-frustum. If the tapered
    cyl renders with the wrong axis direction, taper
    direction, or scaling, the first project-author
    render will reveal it.
  - The Reducer is rotationally symmetric about Z;
    make render-Reducer (turntable) is sufficient.
  - Bore is stepped (matches commercial brass
    plumbing); an alternative uniform-bore variant is
    not queued because the use case is not yet clear.

* Phase 1 status

  Per-component:
    Descriptive taxonomy        ~99% (no change)
    Illustrations                ~56% (no change)
    Per-size dimension tables   100% (unchanged)
    Validation pass             100% (unchanged)
    BSPP 3D model library       ~56% (up from ~50%)

  Weighted Phase 1 aggregate: roughly 79.8% (up from
  ~77.7% at 0.12.0). The ~2.1 percentage-point
  increment is larger than the Tee/Cross jumps (~1.75
  pts each) because the Reducer introduces a new
  construction idiom (frustum-based conical
  transition) that the Hose Tail will reuse, not just
  an incremental extension of existing patterns.


Version 0.12.0 (2026-05-15)
===========================

Minor-version bump. The 0.11.x patch line closed with the
Tee defect-fix (0.11.1) verified by project-author render
review. The 0.12.0 minor version opens by adding the Cross
(G-04) --- the four-port symmetric extension of the Tee ---
and by formalising the side-by-side review discipline that
the 0.11.0 Tee defect revealed was missing.

Project-author timestamp: [2026-05-15 Fri 15:48].

* Cross model added (G-04)

  Models/G04_Cross/Cross.scad is the seventh fitting in
  the library. 4 x M BSPP Cross with four perpendicular
  arms meeting at a central junction: port A at -X, port
  B at +X (colinear run), port C at +Z, port D at -Z
  (colinear branches). All four ports share the same
  nominal size; reducing crosses (different size on the
  branch pair) are queued in FutureResearch.org.

  Geometric construction: union of two centred
  perpendicular cylinders (one along X covering arms A
  and B, one along Z covering arms C and D), four
  threaded rods at the ports, minus a + cross-section
  bore (two centred bore cylinders, one along X, one
  along Z).

  Symmetric construction: the Cross is /simpler/ in
  code than the Tee despite having one more port,
  because both body cylinders take the same form
  (centred, length 2 * lPlain + 2 * lEps where
  lPlain = arm_length - thread_length). The Tee has an
  asymmetric branch body that the Cross does not need.

  Registered for rendering: make render-Cross,
  make render-Cross-hemisphere, make render-Cross-sphere.

* Side-by-Side Body-Thread Length Review (DevelopmentStandard.org)

  New sub-section under § Programming Source Code /
  OpenSCAD Specific Conventions. Codifies the discipline
  the assistant should have applied at 0.11.0 Tee
  review: before delivering a new fitting that combines
  a body cylinder with one or more threaded ports, the
  assistant tabulates the body-cylinder length
  expressions of every existing fitting alongside the
  new fitting's and confirms the new entry follows the
  established pattern.

  The pattern: body cylinder occupies the PLAIN section
  of the arm (junction to thread start), with an eps
  overhang on each endcap into the adjacent thread's
  volume. Skipping the body-trim step (as the 0.11.0
  Tee did) leaves the thread covered by the body and
  produces the missing-thread defect.

  Practical form: a comment block in the new fitting's
  _implementation module includes a table with one row
  per existing fitting. The 0.12.0 Cross is the first
  model written under this discipline; its _cross
  module contains the inaugural example.

* Tee (0.11.1) verified by project-author render review

  Project-author rendered the 0.11.1 Tee in full-sphere
  mode and uploaded the resulting 182-frame tarball at
  0.12.0. Project-author verdict: "now the tee is
  correct, with threads for a M x M x M version". The
  FutureResearch entry for the Tee missing-threads
  defect is updated to FIXED at 0.11.1, VERIFIED at
  0.12.0.

* Honest disclosures

  - No end-to-end render of the new Cross in the
    assistant's environment. The Cross was authored by
    reading the 0.11.1 corrected Tee pattern and
    applying it symmetrically to four arms.
  - The Cross.scad is the first model written under
    the side-by-side review discipline. If the
    discipline fails to catch a defect visible on the
    project-author's render, that's a signal that the
    discipline needs further refinement.
  - Likely defect surfaces (lower probability than the
    body-thread length issue, but worth listing): the
    four thread orient values (LEFT/RIGHT/UP/DOWN), or
    the bore coplanarity at the central junction where
    the two bore cylinders share a midpoint.

* Phase 1 status

  Per-component:
    Descriptive taxonomy        ~99% (no change)
    Illustrations                ~56% (no change)
    Per-size dimension tables   100% (unchanged)
    Validation pass             100% (unchanged)
    BSPP 3D model library       ~50% (up from ~45%)

  Weighted Phase 1 aggregate: roughly 77.7% (up from
  ~75.95% at 0.11.1). The ~1.75 percentage-point
  increment matches the 0.10.2 -> 0.11.0 jump (Tee
  added), reflecting that both Tee and Cross are
  incremental fittings that extend established
  patterns. The remaining geometry classes (Reducer,
  Union, Hose Tail) each introduce new construction
  idioms and will carry proportionally more weight.


Version 0.11.1 (2026-05-15)
===========================

Defect-fix patch. The 0.11.0 Tee shipped with the threads on
all three ports geometrically present but visually hidden:
the body cylinders were sized to the full arm_length, and
because the thread OD is smaller than the body OD by design
(bsppfit_major_od ≈ 20.96 mm versus arm_od = 24.96 mm for
G1/2), the body covered the threads. The boolean union
displayed the body's smooth surface and hid the thread
profile entirely.

The project author noticed this on first render of the
0.11.0 delivery ("seem alright from my standpoint with the
exception of the missing threading") and asked whether the
0.11.0 Tee was M x M x M or F x F x F. The intent at
0.11.0 was always M x M x M (the docstring's F-02 Gender
declaration is explicit), so the ambiguity was a consequence
of the missing-thread defect rather than an underspecified
docstring.

Project-author timestamp: [2026-05-15 Fri 15:27].

* Tee thread fix (Models/G03_Tee/Tee.scad)

  Single conceptual change: body cylinders are now sized to
  the plain-cylinder length between the junction and the
  thread start, not the full arm_length. The pattern mirrors
  the Nipple's body-between-threads arrangement and matches
  what the Elbow already does for its straight arm sections.

  Code changes in the _tee module:
  - New local: lPlain = arm_length - thread_length.
  - Run body: l = 2 * lPlain + 2 * lEps (was: 2 * arm_length).
    The eps overhang on each end prevents coplanar faces at
    the body-thread interface.
  - Branch body: l = lPlain + lEps with down(lEps) +
    anchor = BOTTOM (was: l = arm_length with
    anchor = BOTTOM at z=0). Spans z in [-eps, lPlain] so
    the branch overlaps the run body by eps at the junction.

  Bore subtraction is unchanged (the bore must pass through
  both body and thread regions in full).

  Construction commentary at the top of _tee updated to
  describe the new lengths and to explicitly mark the
  0.11.0-to-0.11.1 transition for future reviewers.

* No other changes

  This is a minimal defect-fix patch. The wrapper docstring
  (M x M x M Gender declaration), parameter set, attachable
  bounding box, assertions, gallery module, test area, and
  Makefile registration are all unchanged from 0.11.0. The
  BOSL2 idiom usage is unchanged. The FutureResearch
  entries are unchanged.

* Honest disclosures

  - No end-to-end render of the fix performed in the
    assistant's environment. The fix was authored by
    reading the Nipple's working body-between-threads
    pattern and copying it to the Tee. First end-to-end
    verification is the project author's
    make render-Tee-sphere on receipt.
  - The fix should produce visibly correct threads on all
    three ports with a small shoulder step at each
    body-thread junction (the natural consequence of
    arm_od > bsppfit_major_od by 4 mm at the default,
    matching the commercial reference photos uploaded
    with the bug report).
  - This defect was not caught at 0.11.0 review. Source
    review covered bracket balance, BOSL2 idiom
    compliance, and parameter consistency, but did not
    place Nipple/Elbow/Tee body-cylinder length
    expressions side-by-side. A side-by-side review
    discipline note is queued in FutureResearch.org.

* Phase 1 status

  Unchanged from 0.11.0 nominally. The 0.11.1 fix is a
  defect repair, not a new contribution; the Phase 1
  aggregate is a count of what is present, not what is
  correctly rendered, and the 0.11.0 Tee was already
  counted in the model library.

  Per-component (no change):
    Descriptive taxonomy        ~99%
    Illustrations                ~56%
    Per-size dimension tables   100%
    Validation pass             100%
    BSPP 3D model library       ~45%

  Weighted Phase 1 aggregate: ~75.95% (unchanged).


Version 0.11.0 (2026-05-15)
===========================

Minor-version bump: the 0.10.x patch line closed with the
Elbow geometric rewrite (0.10.2) verified by project-author
review. The 0.11.0 minor version opens by adding the Tee
(G-03) --- the third of the four most-common BSPP fitting
types after the Nipple (G-01) and the Elbow (G-02) already
in the library.

Project-author timestamp: [2026-05-15 Fri 10:11].

* Tee model added (G-03)

  Models/G03_Tee/Tee.scad is the sixth fitting in the
  library. M x M x M BSPP Tee with three perpendicular
  arms meeting at a central junction: run port A at -X,
  run port B at +X (colinear), branch port C at +Z. All
  three ports share the same nominal size in this 0.11.0
  implementation; reducing tees (different size on the
  branch) are queued in FutureResearch.org.

  Geometric construction: union of three perpendicular
  cylinders for the body, three threaded rods at the open
  ends, minus a T-shaped bore. The construction uses BOSL2
  idioms throughout per the expanded standard (see below).

  Registered for rendering: make render-Tee,
  make render-Tee-hemisphere, make render-Tee-sphere
  available alongside the existing Nipple, Elbow, Cap,
  Plug, HexBush targets.

* BOSL2 Idiom Preference expanded (DevelopmentStandard.org)

  The existing § Programming Source Code / OpenSCAD
  Specific Conventions / BOSL2 Positioning and Rotation
  Functions subsection is renamed to BOSL2 Idiom Preference
  (positioning, rotation, primitives) and expanded:

  - General rule: when there is a more evolved or simpler,
    readable variant in BOSL2 for a given OpenSCAD
    primitive, use the BOSL2 form.
  - Scope clause: applies to new code and to deliberate
    touches on existing code; does not mandate retroactive
    rewrites.
  - Primitives: prefer cuboid over cube (for the
    attachment system, chamfer, and rounding parameters)
    and cyl over cylinder (already standard practice in
    the project).
  - Off-axis primitives: prefer cyl(orient = RIGHT) over
    rotate(...) cyl(...); prefer torus(orient = BACK)
    over rotate([90, 0, 0]) torus(...).

  The 0.10.2 Elbow.scad is the most prominent existing-
  code violator; reflow queued in FutureResearch.org for
  the next deliberate touch on that file (the geometry is
  verified-correct and a no-functional-change reflow
  would risk introducing regressions).

* Elbow (0.10.2) verified by project-author render review

  Project-author rendered the 0.10.2 Elbow(size = 1/2) in
  full-sphere mode and uploaded the resulting 182-frame
  tarball at 0.11.0. Project-author verdict: "from my
  standpoint it seems correct". The FutureResearch entry
  for the Elbow geometric defects is updated to ADDRESSED
  at 0.10.2 and VERIFIED at 0.11.0.

* BOSL2 source-access correction

  The BOSL2-master.zip has been at
  /mnt/user-data/uploads/BOSL2-master.zip since iteration
  0.9.0. The assistant overlooked it and issued false
  disclaimers in iterations 0.10.0 through 0.10.2 about
  "BOSL2 source access not available in my environment".
  The standing 0.10.2 disclaimer about "BOSL2's
  torus(or, ir) parameter-name assumption" is now
  resolved: the BOSL2 source confirms torus accepts those
  parameter names (shapes3d.scad:3880).

* Hex-corner F x F elbow: deferred to facet audit

  Project-author uploaded four reference photos of F x F
  brass elbows with hex-shaped corner bodies. The
  "hex corner F x F elbow" is plausibly a parametric
  variant of G-02 Elbow, or a distinct entry in G-02, or
  evidence that hex grip on female fittings is a cross-
  cutting facet. The placement question is deferred to
  the §24.3.4 facet audit against ISO 12006-2 and
  UniClass 2015. The 0.11.0 library does not implement
  the F x F hex-corner variant.

  Note: this is a different pattern from the 0.10.0
  M x M corner_hex misfeature (deleted in 0.10.2). On
  M x M, the hex did not belong because the run-flat
  surfaces of the male arms can carry a wrench grip; on
  F x F, the hex IS geometrically correct because the
  female ports have no thread-flat surfaces of their own.

* Phase 1 status

  Per-component:
    Descriptive taxonomy        ~99% (no change)
    Illustrations                ~56% (no change)
    Per-size dimension tables   100% (unchanged)
    Validation pass             100% (unchanged)
    BSPP 3D model library       ~45% (up from ~40%)

  Weighted Phase 1 aggregate: roughly 75.95% (up from
  ~74.2% at 0.10.2). The ~1.75 percentage-point
  increment reflects the addition of the Tee as the
  sixth end-to-end fitting; the larger jump than
  0.10.2's ~1.05 points is because 0.10.2 was a
  refinement of an existing model rather than a new
  class.


Version 0.10.2 (2026-05-14)
===========================

Bloom-and-refine iteration. Project-author timestamp:
[2026-05-14 Thu 17:19]. Two strands of work landed in parallel:

  - The Elbow geometry rewrite. Three project-author-identified
    defects from iteration 0.10.0 finally addressed: hex grip
    removed, default arm length increased to commercial G1/2
    proportions, cylinder-union corner joint replaced by a
    smooth swept bend (quarter-torus).
  - Render pipeline extension. Every render target now produces
    a tar archive AND an MP4 alongside the PNG sequence.

The OpenSCAD 2025.12.09 development build with the Manifold
backend rendered the 0.10.1 Elbow sphere in 35 seconds versus
10 minutes with the 2021.01 system package --- empirical
confirmation that the 0.10.1 --with-openscad infrastructure
landed correctly.

* Elbow geometry rewrite (Models/G02_Elbow/Elbow.scad)

  Three changes to the Elbow:

  1. corner_hex parameter REMOVED. The 0.9.9-introduced hex
     flange was commercially incorrect for M x M brass elbows;
     0.10.2 deletes it entirely (not deprecated, not
     toggleable). If a future female-elbow or socket-elbow
     variant needs a hex grip, that should be a separate
     module.

  2. Default arm_length increased. New formula:
     thread_length + bend_radius + 1.5 mm. For G1/2 with
     defaults this gives approximately 22.7 mm, within 1.2 mm
     of the commercial PVC-Welt G1/2 reference L = 21.5 mm.

  3. Quarter-torus swept bend at the corner. The
     cylinder-union joint (which produced the + silhouette
     degeneration at the corner --- the "miter not closed"
     defect) is replaced by a smooth quarter-torus. The bend
     centerline arc goes from (0, 0, bend_radius) to
     (bend_radius, 0, 0), with major radius bend_radius and
     tube radius arm_od/2. The bore follows the same path
     with smaller radii.

  New parameter:
  - bend_radius (default arm_od/2 + 0.5 mm): major radius of
    the quarter-torus corner bend. The +0.5 mm offset above
    the minimum keeps the inner-curve radius positive and
    avoids the horn-torus singularity at exactly arm_od/2.

  Four new asserts validate the geometry: arm_length must be
  at least bend_radius + thread_length; bend_radius must be
  at least arm_od/2; bore must be non-negative; bore must be
  less than 2 * bend_radius.

* Render pipeline: tar + MP4 in every target

  bin/render-views gains a --tar flag (parallel to --mp4).
  build_tar uses Python's standard tarfile module to produce
  an uncompressed tar archive <Model>_<mode>.tar containing
  the produced PNGs. Uncompressed because the PNGs are
  already zlib-compressed.

  build_mp4 becomes mode-aware: filename is now
  <Model>_<mode>.mp4 (was always <Model>_turntable.mp4
  regardless of actual mode in 0.10.1).

  Models/Makefile.am: every render target (render-<Model>,
  render-<Model>-hemisphere, render-<Model>-sphere, and the
  aggregate render) now passes --tar --mp4 unconditionally.
  The 0.10.1 render-<Model>-mp4 target is kept as a
  deprecated alias.

  make help output updated to show the three artefacts each
  target produces (PNG sequence, tar, MP4).

* Documentation

  DevelopmentStandard.org § Model Rendering Pipeline:
  - Quick start subsection: every example shows the
    three-artefact output.
  - Architecture subsection: the MP4 output description is
    updated; tar artefact added.
  - Make targets subsection: each target's three output
    artefacts are listed; -mp4 suffix documented as
    deprecated.

  FutureResearch.org: the "Elbow geometric defects identified
  0.9.9" entry is marked ADDRESSED at 0.10.2 with sub-bullets
  documenting each of (a) hex removal, (b) arm-length
  increase, (c) quarter-torus swept bend.

* Honest disclosures

  - No end-to-end render performed in the assistant's
    environment (OpenSCAD still not installed). The Elbow
    rewrite was authored without running OpenSCAD against
    it. First end-to-end test is the project author's
    make render-Elbow-sphere on receipt.
  - Quarter-torus geometry is unverified. The clipping cube
    position, torus parameter ordering, and join planes
    were derived analytically.
  - BOSL2's torus(or, ir) parameter names are used directly;
    if the BOSL2 module uses different names (e.g. od/id),
    the script will fail at parse time.
  - The horn-torus singularity at bend_radius = arm_od/2 is
    avoided by the +0.5 mm default offset. The asserts
    permit users to pass the exact boundary if they want.
  - --tar flag tested in isolation with three dummy PNG
    files only; not tested against an actual render output.
  - Other fittings (Tee, Cross, Reducer, Union, HoseTail)
    not started in this iteration. The Elbow rewrite +
    render-pipeline work consumed the available iteration
    budget; the project author's "if there is resource"
    qualifier was respected.

* Phase 1 status

  Per-component:
    Descriptive taxonomy        ~99% (no change)
    Illustrations                ~56% (no change)
    Per-size dimension tables   100% (unchanged)
    Validation pass             100% (unchanged)
    BSPP 3D model library       ~40% (up from ~37%)

  Weighted Phase 1 aggregate: roughly 74.2% (up from
  ~73.15% at 0.10.1). The increment reflects the Elbow's
  quality improvement; the model count is unchanged (Elbow
  is still one of five existing models, but is now
  commercially correct rather than partially correct).


Version 0.10.1 (2026-05-13)
===========================

Refinement-of-infrastructure iteration on the 0.10.0
communication jig. Project-author timestamp:
[2026-05-13 Wed 10:38]. Project author ran the 0.10.0 jig on
the Elbow, uploaded the resulting PNG tarball and MP4
turntable for review, and returned seven items of feedback.
All seven are addressed in this iteration.

The Elbow geometry defects (hex grip, short arms, "miter not
closed") that the 0.10.0 jig made visible remain queued for
0.10.2.

* Seven items of project-author feedback addressed

  1. Unix tool naming. bin/render-views.py renamed to
     bin/render-views (no extension; shebang handles
     execution).

  2. PNG filename: terse positional form. Old
     "Elbow_lat+00_lon+090_frame_010.png" becomes
     "Elbow_010+00+090.png". Frame number first (so lex order
     matches frame order unambiguously); positional encoding
     with sign characters as implicit separators; no labels.

  3. Note for FutureResearch: python3/openscad/ffmpeg become
     mandatory at configure time once renders feed taxonomy
     illustrations. Trigger documented; effort estimated
     (30 minutes).

  4. Manual pages for the three bin/ tools:
     - Doc/man/checkxref.1
     - Doc/man/applyxref.1
     - Doc/man/render-views.1
     Standard groff, section 1. Ship via EXTRA_DIST. Install
     under $(mandir)/man1/ via man_MANS deferred to when
     "make install" exists.

  5. PNG tarball preferred over MP4 for uploads to the
     assistant: filenames carry the (frame, lat, lon)
     coordinate metadata; MP4 frames lose the metadata
     during ffmpeg extraction. Both formats produced by
     make render-<Model>-mp4; tarball is the recommended
     review-upload form. Workflow observation, not a rule.

  6. Discoverability of the invocation. New "make help"
     target in Models/Makefile.am lists every render target
     with one-line descriptions. New "Quick start" subsection
     at the top of Doc/DevelopmentStandard.org "Model
     Rendering Pipeline" gives the common invocations first.
     Both address the project-author's observation that the
     journal was the wrong place to look for "how do I
     invoke this?"

  7. Configure-time OpenSCAD selection. ./configure now
     accepts --with-openscad=PATH and --with-ffmpeg=PATH
     overrides. The chosen binaries propagate to every
     "make render-*" invocation via the Makefile. The
     renderer script also accepts --openscad-binary PATH
     and --ffmpeg-binary PATH for standalone invocations.

* Honest disclosures

  - No end-to-end test in the assistant's environment.
    OpenSCAD still not installed where the assistant works;
    the renderer's modified CLI, filename format, and
    binary-selection logic were tested in isolation but not
    against a real .scad file.
  - Manpages not validated with man(1). They follow standard
    groff macros but rendering was not tested.
  - The new "make help" target uses a POSIX sh-loop over
    RENDER_MODELS; not tested but should work on any POSIX
    shell.
  - The render-views path-vs-PATH detection uses a Python
    boolean-precedence idiom that is correct on Linux (where
    os.altsep is None) but is not tested on Windows.

* Phase 1 status

  Per-component (no change from 0.10.0):
    Descriptive taxonomy        ~99%
    Illustrations                ~56%
    Per-size dimension tables   100%
    Validation pass             100%
    BSPP 3D model library       ~37%

  Weighted Phase 1 aggregate: ~73.15%, unchanged from
  0.10.0. Refinement of infrastructure does not move Phase 1
  directly; the value is in reducing friction on future
  iterations.


Version 0.10.0 (2026-05-12)
===========================

Communication-jig iteration. Project-author timestamp:
[2026-05-12 Tue 20:01]. No new fitting and no refinement of an
existing fitting; the entire iteration is infrastructure for
future iterations: a rendering pipeline that removes view-
interpretation ambiguity between project author and assistant.

Version-number choice: 0.9.9 to 0.10.0 (minor bump rather than
patch to 0.9.10). Three reasons: a new top-level tool
(bin/render-views.py) on the same scale as bin/checkxref; new
configure-time dependencies (python3, openscad, ffmpeg); new
Renders/ subdirectory layout under each model's folder. These
are structural additions, not refinements.

* Communication-jig: spherical-sampling rendering pipeline

  Triggered by the cumulative misreads of the Hex Bush (0.9.7),
  Elbow (0.9.8), and Elbow refinement (0.9.9) renders during
  multi-view PNG reviews. The project author proposed the
  approach; the assistant designed and implemented it under
  /Option B/ (build the jig first; fix the resulting Elbow
  defects in 0.10.1).

  New tool: bin/render-views.py. Python 3, no third-party
  dependencies. Drives OpenSCAD in batch mode, one invocation
  per frame, sampling camera viewpoints on a sphere centred at
  the model's local origin. Each PNG is named with the spherical
  coordinates (latitude, longitude) of its camera position plus
  an ordinal frame number, so the viewpoint is identifiable
  from the filename alone.

  Coverage modes:
  - turntable  : equator only, 36 frames every 10 degrees.
                 Default. Fast. Sufficient for shape
                 understanding and routine communication.
  - hemisphere : equator + +30/+60 latitudes + north pole, 109
                 frames.
  - sphere     : adds -30/-60 and south pole, 182 frames. Use
                 when the model has dissimilar top and bottom
                 faces.

  Filename format:
    <Model>_lat{sign}DD_lon{sign}DDD_frame_NNN.png
  Example:
    Elbow_lat+00_lon+090_frame_010.png

  Latitude is signed two-digit, longitude signed three-digit,
  frame number zero-padded three-digit. The padding makes
  lexicographic sort order match frame order, which simplifies
  ffmpeg glob-based input.

  Image size: 1024x1024 (configurable via --imgsize WxH).

  OpenSCAD invocation uses --render (full geometry pipeline,
  excludes preview-mode axis overlay) plus --viewall (auto-fit
  the camera distance to the model bounding box) plus the
  6-argument --camera=eyex,eyey,eyez,centerx,centery,centerz
  LookAt form.

  Optional MP4 turntable via ffmpeg invoked from the script
  with --mp4 (additional --fps INT to control frame rate;
  default 12 fps gives a 3-second clip in turntable mode).

* Makefile integration

  Models/Makefile.am gains a generator-pattern that emits four
  targets per registered model:
  - make render-<Model>             (turntable mode)
  - make render-<Model>-hemisphere
  - make render-<Model>-sphere
  - make render-<Model>-mp4         (turntable + MP4)

  Plus an aggregate "make render" that runs turntable mode for
  every registered model.

  The list of registered models lives in a single RENDER_MODELS
  variable, so adding a new model only needs one line of
  Makefile change.

  Cleanup: clean-local removes per-model Renders/
  subdirectories; "make clean" propagates through clean-local.

  The render targets are NOT part of "make all" because OpenSCAD
  is not in the project's standing build dependencies and the
  renders are not a Phase-1 deliverable in the same sense the
  source files are.

* Configure-time tool checks

  configure.ac adds three optional dependency checks:
  - python3   : required by the render script.
  - openscad  : required by all render targets.
  - ffmpeg    : required only by --mp4 / make render-*-mp4.

  All are warnings, not errors. Configure summary block now
  lists them under "Optional (render pipeline)".

* Documentation

  Doc/DevelopmentStandard.org gains a new section
  "Model Rendering Pipeline" before the Conclusion. Documents
  the architecture, coverage modes, make targets, dependencies,
  coordinate convention, image size/rendering mode, and
  cross-platform note.

  Doc/FutureResearch.org: original 0.9.0 Render pipeline stretch
  goal marked as superseded. New queued items: cross-platform
  support (macOS, Windows); Renders/ git-tracking decision;
  Elbow defects (a)..(c) from the 0.10.0 project-author review.

* Elbow defects (queued for 0.10.1)

  Project-author review of the 0.9.9 Elbow against the
  PVC-Welt commercial schematic identified three defects to
  fix in 0.10.1 with the help of the new rendering jig:

  (a) Hex grip is commercially incorrect for M x M elbows.
      Commercial brass M x M elbows have smooth cylindrical
      arms with no hex flange. Plan: revert corner_hex default
      to false; keep the parameter for opt-in.

  (b) Arms are too short. Commercial G1/2 has L=21.5 mm versus
      the 0.9.9 default of 16.2 mm. Plan: increase the default.

  (c) "The miter is not closed". The 0.9.9 cylinder-union joint
      should be replaced by a smooth swept bend (a quarter-torus
      at the corner). Plan: rewrite the corner geometry as a
      quarter-torus path-sweep.

* Honest disclosures

  - End-to-end test unavailable in the assistant's environment.
    OpenSCAD is not installed where the assistant works, so the
    renderer could not be executed against an actual .scad file
    before delivery. Tested: Python CLI, spherical-to-Cartesian
    math, frame-list generation for all three modes, filename
    formatter. NOT tested: actual OpenSCAD invocation, --camera
    argument format, --render axis suppression, ffmpeg MP4
    generation. Project-author execution will be the first
    end-to-end test.
  - Camera viewpoint formula not empirically verified. If
    OpenSCAD's LookAt interprets the eye position differently
    from the assumed convention (e.g. uses -Z instead of +Z as
    default up), the rendered viewpoints may be rotated or
    mirrored from intent. Adjustable in 0.10.1.
  - --render axis suppression not verified. If axes appear in
    PNGs despite --render, follow-up fix would crop with
    Pillow.
  - Cross-platform deferred. 0.10.0 targets GNU/Linux only.
  - No actual renders ship in the 0.10.0 delivery. The
    infrastructure ships; project author runs "make render"
    on receipt to populate the Renders/ directories.

* Phase 1 status

  Per-component (no change from 0.9.9):
    Descriptive taxonomy        ~99%
    Illustrations                ~56%
    Per-size dimension tables   100%
    Validation pass             100%
    BSPP 3D model library       ~37%

  Weighted Phase 1 aggregate: roughly 73.15%, unchanged from
  0.9.9. Infrastructure iterations do not increment Phase 1
  percentages directly; their value is amortised over future
  iterations.


Version 0.9.9 (2026-05-12)
==========================

Refinement iteration responding to project-author review of the
0.9.8 Elbow renders. Project-author timestamp:
[2026-05-12 Tue 15:30]. Comment: "this is a good start but
which requires some enhancements". Five views (front, top,
bottom, left, right) uploaded for guidance, no specific defect
called out; the assistant identified enhancements from the
views.

* Elbow refinements

  Three changes to Models/G02_Elbow/Elbow.scad:

  1. Optional hex grip body at the corner. New parameters:
     - corner_hex (boolean, default true): when true, adds a
       hex prism at the corner with axis along +Y
       (perpendicular to both arm axes). When false, the
       0.9.8 design (plain cylindrical arms only) is
       preserved.
     - corner_hex_height (default arm_od + 2 mm): axial height
       along +Y, centred on the elbow's XZ plane of symmetry.
     - corner_hex_od (default arm_od + 4 mm): across-flats
       diameter. The +4 mm margin puts the hex slightly proud
       of the arm cylinders.

     The hex prism's axis along +Y means the hex's six flats
     face directions in the XZ plane (visible as a hexagon in
     front and back views). Wrench grip is available from
     either side of the elbow's plane of symmetry. This
     matches commercial brass elbow castings.

  2. Default arm_length increased from thread_length + 5 mm to
     thread_length + 8 mm. The 0.9.8 default produced a
     visually compact elbow where the corner zone dominated;
     +8 mm gives more commercial-realistic proportions. For
     G1/2: 0.9.8 default 13.2 mm vs 0.9.9 default 16.2 mm.

  3. Cleaned-up eps-overlap pattern at the corner. The 0.9.8
     construction extended each arm cylinder by lEps INTO the
     corner via translate by -lEps; this relied on the eps
     overlap to ensure clean booleans. The 0.9.9 pattern
     places each arm at its natural corner-side end (no
     negative offset); the natural Steinmetz-solid
     intersection of two perpendicular cylinders provides
     clean boolean unions without the eps. eps is retained
     only at the bore subtractions' open ends.

  The attachable bounding-box approximation gains awareness of
  the corner hex: Y extent is now max(arm_od, corner_hex_height)
  when the hex is present.

* Honest disclosures

  - No specific defect was named by the project author. The
    "enhancements" comment is open-ended; the assistant chose
    enhancements based on inspection of the renders. If the
    intended enhancement is different (chamfer at thread/plain
    seam, fillet at inner corner, long-radius bend, etc.), the
    next iteration can revisit.
  - Elbow geometry with hex grip unverified by render.
  - Corner hex dimensions (arm_od + 4 mm flats, arm_od + 2 mm
    height) are heuristics analogous to the Cap/Plug head_od
    and HexBush hex_od rules, not catalogue-verified.
  - The corner_hex = true default is a commercial-match
    choice; corner_hex = false preserves the 0.9.8 design for
    users who want a compact elbow.

* Phase 1 status

  Per-component:
    Descriptive taxonomy        ~99% (no change in content)
    Illustrations                ~56% (no change)
    Per-size dimension tables   100% (unchanged)
    Validation pass             100% (unchanged)
    BSPP 3D model library       ~37% (up from ~35%)

  Weighted Phase 1 aggregate: roughly 73.15% (up from ~72.45%).
  Modest increment from refinement-not-bloom; no new fitting
  class landed. The corner-hex pattern is reusable for Tee,
  Cross, and other multi-port fittings.


Version 0.9.8 (2026-05-12)
==========================

Bloom-and-judgment iteration. Project-author timestamp:
[2026-05-12 Tue 15:03].

* New model: G-02 90-degree mitered elbow

  Models/G02_Elbow/Elbow.scad. First 90-degree mitered male x
  male BSPP elbow. Two arms at 90 degrees to each other, each
  ending in a BSPP external thread, joined at the corner via
  cylinder unions; through-bores cross at the corner forming
  the L-shaped interior channel; the small solid volume at the
  inner corner is the natural inner-edge geometry of a mitered
  elbow.

  Architecture firsts:
  - First model with two ports not on a common axis.
  - First use of off-axis orientation primitives (rotate([0,
    90, 0]) wrapping arm B's +Z-aligned cylinder and thread
    to put them along +X).
  - First fitting where the BOSL2 attachable bounding-box
    approximation visibly under-serves the geometry: the
    elbow is L-shaped, so the cuboid bounding box over-counts
    the unoccupied corner region. Workaround: translate() at
    the caller. Refinement to a custom anchor list queued.

  Public wrapper Elbow() with parameters: size (default 1/2,
  same on both ports), thread_length (undef-resolved to
  useful_thread_length), arm_length (undef-resolved to
  thread_length + 5 mm), arm_od (undef-resolved to
  major_od(size) + 4 mm, raised via bsppfit_safe_wall with
  BSPPFIT_MIN_WALL), bore (undef-resolved to default_bore),
  plus the standard manifold_safe / tol_thread / anchor /
  spin / orient.

  Gallery Elbow_Gallery() renders all 9 supported sizes in a
  single row at the default orientation.

* Manifold-warning investigation under manifold_safe = false:
  deferred

  Project author reported in the 0.9.7 review that
  HexBush(size_male = 1/2, size_female = 1/4, manifold_safe =
  false) emits "PolySet -> Manifold conversion failed:
  NotManifold" followed by OpenSCAD's repair pass which
  completes successfully (Status: NoError). The warning has
  fired on all four prior fittings under the same opt-in.
  Raising $fn does not help; the warning appears at multiple
  sizes.

  Project-author question: investigate now or defer?
  Assistant judgment: defer. Reasoning:
  - The default path (manifold_safe = true) is clean across
    all fittings.
  - The 0.9.2 architecture decision recorded
    manifold_safe = false as an explicit opt-in to authentic
    visuals at the cost of manifold reliability; the warning
    under the opt-in is by definition the documented cost.
  - The repair pass succeeds; the rendered geometry is
    correct.
  - One unified diagnosis at the right time is more
    efficient than per-fitting workarounds applied under
    iteration pressure.

  Risks of delay made explicit:
  - The cause may compound as more blunt-start models are
    added.
  - User opting in for prettier renders sees log noise.
  - If the repair pass ever produces geometry that differs
    subtly from the un-repaired form in a way that matters,
    the issue jumps from "log noise" to "geometry defect".
    This is the strongest argument for not deferring
    indefinitely.

  Trigger for revisiting: a fifth or later fitting showing
  the same warning under blunt-start, OR a user report
  indicating geometry defect under manifold_safe = false.

  Queued as a stretch-goal investigation in
  FutureResearch.org with the reasoning above.

* HexBush renders confirmed (HexBush-top.png,
  HexBush-bottom.png)

  Top and bottom views uploaded with the 0.9.8 input.
  Confirmed: clean hex body, male G1/2 thread protruding
  from the top, female G1/4 cavity opening at the bottom
  with the smaller through-bore continuing up through the
  centre. The mixed-gender + multi-size + wall-thickness
  exercise from 0.9.7 validated by render.

* FutureResearch queue updated

  Elbow marked as landed in 0.9.8; follow-up variants queued
  (45-degree, female, mixed-gender / street elbow, attachable
  refinement to a custom anchor list).

  Manifold-warning investigation queued in Stretch Goals
  with the reasoning, risks, and trigger condition.

* Phase 1 status

  Per-component:
    Descriptive taxonomy        ~99% (no change in content)
    Illustrations                ~56% (no change)
    Per-size dimension tables   100% (unchanged)
    Validation pass             100% (unchanged)
    BSPP 3D model library       ~35% (up from ~30%)

  Weighted Phase 1 aggregate: roughly 72.45% (up from ~70.7%).
  Five fittings now implemented end-to-end (Nipple, Cap, Plug,
  HexBush, Elbow); four of the nine queued geometry classes
  covered (G-01 Straight, G-02 Elbow, G-06 Cap/Plug, G-08
  HexBush). The angular-port case is now exercised, validating
  that the wrapper + underscore-implementation + gallery
  pattern generalises beyond axial fittings.


Version 0.9.7 (2026-05-12)
==========================

Pure-bloom iteration on project-author invitation to continue,
with the explicit hint to "beware of old heuristics to be
applied when needed and discovering new ones if the need
arises, I'm thinking especially at wall thickness".

Project-author timestamp: [2026-05-12 Tue 10:33].

* New model: G-08 Reducing Hex Bush

  Models/G08_HexBush/HexBush.scad. Short two-port fitting that
  reduces one BSPP size to another with opposite gender on
  its two ports: MALE (external) thread on the larger size,
  FEMALE (internal) thread on the smaller. Hex prism body
  serves as wrench grip and as the closure between the two
  thread regions.

  Architecture firsts:
  - First model with two BSPP sizes in one fitting (previous
    models had a single size, or a same-size pair).
  - First model with mixed gender (Nipple was MxM, Cap was
    female-only, Plug was male-only; HexBush is MxF).
  - First model that combines bspp_threaded_rod (external)
    and bspp_threaded_rod(internal = true) in one
    difference() invocation.
  - First user of the new wall-thickness convention.

  Public wrapper HexBush() takes size_male, size_female,
  male_thread_length (undef-resolved to useful-thread-length
  of size_male), female_thread_depth (undef-resolved to
  size_female's), hex_height (undef-resolved to
  female_thread_depth + 4 mm), hex_od (undef-resolved to
  major_od(size_male) + 8 mm and raised via
  bsppfit_safe_wall), bore (undef-resolved to default-bore
  of the smaller size_female), and the standard
  manifold_safe / tol_thread / anchor / spin / orient
  parameters. The size pair defaults to G1/2 male x G1/4
  female, a common reducing ratio in pneumatic catalogues.

  Companion HexBush_Gallery() renders nine common reducing
  ratios in a single row, spanning G1/4 x G1/8 through
  G2 x G1+1/2.

* New convention: wall thickness

  Util/util.scad gains a new section between the tolerance
  section and the bore-heuristic section:

  - Named constant BSPPFIT_MIN_WALL = 1.5 mm. The default
    minimum thickness of material between an internal void
    (thread cavity, through-bore, port opening) and the
    outer surface, or between two adjacent internal voids.
    Rationale: at 0.4 mm FDM nozzle, three extrusion passes
    give 1.2 mm; 1.5 mm adds a safety margin. SLA-style
    thinner walls require an explicit override at the call
    site.

  - Helper function bsppfit_safe_wall(requested_od,
    thread_od, min_wall = BSPPFIT_MIN_WALL): returns the
    larger of requested_od and thread_od + 2*min_wall.

  - Warning module bsppfit_warn_wall_raised(requested_od,
    thread_od, label, min_wall = BSPPFIT_MIN_WALL): echoes
    a warning whenever the helper raises a user-supplied
    OD. The label argument lets the calling module identify
    which OD was raised (e.g. "HexBush hex_od").

  Per-fitting-class min_wall conventions documented in
  util.scad's header and in LibraryOverview.org §Conventions:
  Nipple uses 0.5 (safety floor on middle_od raise, not the
  actual wall thickness); Cap and Plug use 1.5 (matching the
  default); HexBush uses BSPPFIT_MIN_WALL against the larger
  thread's major_od.

  Section numbering in util.scad shifts to accommodate the
  insertion: Tolerance is 4, Wall-thickness is now 5, Bore
  is 6, Self-correcting middle-diameter is 7, Size listing
  is 8, Self-test is 9.

* LibraryOverview folder layout updated

  G06_CapPlug shows Cap.scad and Plug.scad as landed (with
  one-line descriptions each). G08_HexBush shows
  HexBush.scad as landed. util.scad description mentions
  wall-thickness defaults alongside tolerance defaults.

* FutureResearch queue updated

  HexBush.scad marked as landed in 0.9.7. The note records
  the priority promotion ahead of Elbow per the wall-
  thickness hint (HexBush's hex-body geometry is the
  natural exercise of a wall-thickness rule; Elbow's
  angular geometry exercises a different family of
  considerations). Elbow promoted to next in queue.

* Honest disclosures

  - HexBush geometry unverified by render. The construction
    follows the same wrapper + private + gallery +
    manifold-eps pattern as Nipple, Cap, Plug; the novel
    pieces (two sizes, internal+external threads in one
    difference(), wall-thickness safe-raise) are
    adaptations of patterns that work elsewhere. Risk
    areas in the journal entry; project-author render
    will confirm.
  - Wall-thickness 1.5 mm default is FDM-reasonable for
    typical 0.4 mm nozzles. NOT verified against any
    specific BSPP fitting catalogue (commercial walls
    are dictated by pressure rating, not extrusion
    mechanics).
  - HexBush hex_od heuristic (~major_od + 8 mm~) is a
    spot-guess analogous to the Cap/Plug +6 mm rule, not
    catalogue-verified. G1/2 default 28.96 mm is slightly
    above typical commercial (22-27 mm); G2 default
    67.61 mm sits in range (65-75 mm).

* Phase 1 status

  Per-component:
    Descriptive taxonomy        ~99% (no change in content)
    Illustrations                ~56% (no change)
    Per-size dimension tables   100% (unchanged)
    Validation pass             100% (unchanged)
    BSPP 3D model library       ~30% (up from ~25%)

  Weighted Phase 1 aggregate: roughly 70.7% (up from ~68.95%).
  Four fittings now implemented end-to-end (Nipple, Cap, Plug,
  HexBush); three of the nine queued geometry classes covered
  (G-01 Straight, G-06 Cap/Plug, G-08 HexBush). The wall-
  thickness convention is the first project-level scaffold
  addition since the 0.9.2 manifold-safe and bore-heuristic
  conventions.


Version 0.9.6 (2026-05-12)
==========================

Fix-and-bloom iteration. Project-author timestamp:
[2026-05-12 Tue 10:00].

* Minimum Emacs version: 29.1 (enforced at configure time)

  configure.ac now performs an explicit version check on the
  discovered $EMACS binary. If major < 29, or major == 29 and
  minor < 1, configure errors out with an explanation.

  Reason: Doc/batch-init.el uses org-resource-download-policy
  and org-safe-remote-resources to suppress remote-resource
  fetching during export. These defcustoms are introduced in
  Org 9.6 (shipped with Emacs 29.1). On older Emacs the
  boundp-guarded setq is silently a no-op, so the user gets
  no benefit from the 0.9.5 fix --- and the documentation
  build hangs on Catalogue.org.

  Doc/DevelopmentStandard.org §Dependencies records the
  minimum version requirement with the same rationale. The
  configure summary block prints the discovered Emacs version
  alongside the binary path.

* Catalogue.pdf generation deferred

  The 0.9.5 attempt to suppress remote-resource fetching via
  org-resource-download-policy = nil did NOT fix the
  Catalogue.org PDF-export hang. The traceback shows
  org-export-link--remote-local-copy still goes through
  org-persist-register / org-persist-write:url, which hits
  the "considered unsafe" check independently of the
  download-policy variable.

  Project-author decision: defer the fix. Comment out
  SUBDIRS = Illustrations in Doc/Makefile.am so the default
  `make` target skips Catalogue.pdf entirely. The HTML
  version (which does NOT trigger the broken code path)
  still builds and is sufficient for the Catalogue's
  current purpose (a working document expected to disappear
  once all illustration slots are filled).

  The Doc/Illustrations directory still has its Makefile.am
  and is still registered in AC_CONFIG_FILES, so:
  - `make -C Doc/Illustrations html` still builds
    Catalogue.html on demand.
  - The bsppfit/publish-all run (HTML build) still includes
    the illustrations-component and produces Catalogue.html.
  - The project-root `html-export` target now invokes
    `$(MAKE) -C Doc/Illustrations html` explicitly to
    bundle Catalogue.html in the deployment archive
    (Catalogue.pdf is dropped from the bundle list).

  To restore Catalogue.pdf generation when the Org /
  org-persist interaction is fixed, uncomment the SUBDIRS
  line in Doc/Makefile.am.

* New model: G-06 Plug

  Models/G06_CapPlug/Plug.scad. Pair-completes the
  terminating-fittings group started with Cap in 0.9.5.

  - Cap (0.9.5): female thread, screws ONTO a male pipe end.
  - Plug (0.9.6): male thread, screws INTO a female pipe port.

  Construction mirrors Cap: solid head on top (hex default,
  round optional), threaded shank below, no through-bore.
  The shank uses BOSL2's bspp_threaded_rod (external thread,
  default). union() instead of difference() because plug has
  no internal cavity. Manifold-fix epsilon at the head/shank
  seam.

  Public Plug() wrapper mirrors Cap()'s parameter signature.
  Companion Plug_Gallery() module renders all 9 supported
  sizes in a single row, hex heads only.

* Bore-heuristic verification --- Cap (and Plug) status

  Project author asked whether the bore-heuristic
  verification (per the 0.9.2 convention) was done for
  Cap.scad. Answer: yes, the cap/plug exception to pipe
  semantics applies, so no bore is present and the 0.7 *
  minor_od heuristic does not apply.

  The adjacent head_od heuristic (default major_od(size) +
  6 mm) was NOT formally verified against trade catalogues
  in 0.9.5. Spot-checks for G1/2 (default 26.96 mm vs
  commercial 22-26 mm) and G2 (default 65.61 mm vs
  commercial 60-75 mm) show the rule is in the ballpark
  but at the upper end of typical commercial sizes. A
  wider catalogue sweep is queued in FutureResearch.org.
  Plug.scad inherits the same heuristic for consistency
  with Cap.

* Phase 1 status

  Per-component:
    Descriptive taxonomy        ~99% (no change in content)
    Illustrations                ~56% (no change)
    Per-size dimension tables   100% (unchanged)
    Validation pass             100% (unchanged)
    BSPP 3D model library       ~25% (up from ~22%)

  Weighted Phase 1 aggregate: roughly 68.95% (up from ~67.9%).
  Three fittings now implemented end-to-end (Nipple, Cap,
  Plug); the G-06 Cap/Plug geometry-class group is complete.


Version 0.9.5 (2026-05-11)
==========================

Bug-fix-plus-bloom iteration. Project-author timestamp:
[2026-05-11 Mon 19:45]. Five defects/observations addressed
and one new model added.

* Default `make` target restored

  Two independent causes broke `make all` on the 0.9.4 build:

  - The 0.9.4 custom `pdf-recursive` and `html-recursive`
    targets in Doc/Makefile.am collided with automake's
    auto-generated targets of the same names (which
    implement SUBDIRS recursion). Automake emitted
    "overriding recipe for target 'pdf-recursive'" and our
    versions replaced the auto-generated ones, breaking
    the recursion mechanism. The custom targets are
    REMOVED in 0.9.5; automake's auto-generated versions
    are restored.

  - Catalogue.org includes URLs to external sources
    (notably Wikimedia Commons SVGs). Org's PDF exporter
    tried to download these via
    org-export-link--remote-local-copy and looped
    indefinitely under batch mode when Emacs's security
    policy rejected the download as "considered unsafe".
    Doc/batch-init.el now sets
    org-resource-download-policy and
    org-safe-remote-resources to nil (with boundp guards
    for older Emacs), so no remote-fetch is attempted
    during export. URLs in the Catalogue render as plain
    hyperlinks, which is what the Catalogue intends.

* html-export archive layout corrected

  Removed the tar --transform options. Archive contents are
  now rooted at the project layout (Doc/Concept.html etc.)
  rather than nested under bsppfit-html-N.N.N/. Deploy
  instructions adjusted: operator now told to `cd <web-root>`
  before `tar xJf <archive>`.

* Index.html postamble restored

  Doc/Index.org changed `#+OPTIONS: html-postamble:nil
  html-preamble:nil` to `#+OPTIONS: html-preamble:nil`. The
  default `auto` postamble now runs and emits the standard
  author + date + creator block at the bottom of Index.html,
  matching the orthogonality of the other rendered HTML
  pages. The preamble suppression is preserved so Index.html
  doesn't get a near-empty header strip from the project's
  bsppfit/html-preamble function.

* LibraryOverview §Status section refactored

  The §Status section had accumulated one paragraph per
  iteration 0.9.0..0.9.4 describing what changed at each.
  That is the ResearchJournal's job; duplicating it in
  LibraryOverview violated the Constitution's separation
  between /what it is/ (overview) and /how it became this/
  (journal). The 0.9.5 §Status is two paragraphs: the
  library's current state, and a pointer to
  ResearchJournal.org for per-iteration history.

* New model: G-06 Cap

  Models/G06_CapPlug/Cap.scad, the first new model since
  0.9.0. A single-port fitting with internal (female) BSPP
  thread that screws onto a male pipe end, terminated at
  the top by a solid head (hex by default, round optional).
  NO through-bore by design --- exercises the cap/plug
  exception to pipe semantics recorded in
  LibraryOverview.org §Conventions in iteration 0.9.2.

  Parameters mirror the Nipple convention: numeric `size`,
  `thread_depth` (default useful-thread-length), `head_height`
  (default 6 mm), `head_od` (default major_od(size) + 6 mm),
  `head_shape` ("hex"|"round", default "hex"),
  `manifold_safe` (default true), `tol_thread` (default
  BSPPFIT_TOL_THREAD), and the BOSL2 attachment-system
  parameters anchor/spin/orient.

  Companion Cap_Gallery() module renders all 9 supported
  sizes side by side. Plug counterpart (external thread,
  screws into a female port) deferred to a future iteration;
  the directory name G06_CapPlug already accommodates the
  pair.

* Phase 1 status

  Per-component:
    Descriptive taxonomy        ~99% (no change in content)
    Illustrations                ~56% (no change)
    Per-size dimension tables   100% (unchanged)
    Validation pass             100% (unchanged)
    BSPP 3D model library       ~22% (up from ~15.5%)

  Weighted Phase 1 aggregate: roughly 67.9% (up from ~65.6%).
  The ~2.3% increment reflects the first new geometry class
  since 0.9.0 (G-06 Cap added to G-01 Straight Nipple),
  bringing the geometry-class count from 1/9 to 2/9 of the
  queued set.

* Tokens counter (project-author question)

  The project author asks whether the assistant has
  access or vision into a token counter. No --- the
  assistant has no telemetry on the conversation's token
  budget. Decisions about iteration scope are based on
  the assistant's subjective sense of remaining
  attention, not on a measured counter.


Version 0.9.4 (2026-05-11)
==========================

Bug-fix iteration responding to project-author execution of the
0.9.3 delivery. Three defects fixed and one infrastructure gap
closed.

* Nipple parameter-default form reverted

  The 0.9.3 reform that put helper-function calls in the
  parameter list (thread_length = bsppfit_useful_thread_length(size))
  fails at runtime: OpenSCAD does NOT bind earlier parameter
  values for use in later default expressions. Nipple reverts
  to the undef + ternary pattern in the body for size-
  dependent defaults (thread_length, middle_od, bore).
  Constant-defaults (middle_length = 8, middle_shape = "hex",
  tol_thread = BSPPFIT_TOL_THREAD, etc.) keep the native form.

  DevelopmentStandard.org §BSPP Model Library --- OpenSCAD
  Style Addenda rewritten with the corrected rule and a
  worked example showing both forms side by side.

* HTML page header: single Index row

  The 0.9.3 switch to a custom bsppfit/html-preamble function
  did not remove the legacy org-html-home/up-format nav: both
  were rendered, producing a two-row header on every page.
  The legacy format is now set to the empty string so only
  the new preamble renders.

* Doc/Illustrations promoted to a proper SUBDIR

  Closes the gap that made the 0.9.3 html-export target
  fail with "Doc/Illustrations/*.pdf: Cannot stat".
  Previously Doc/Makefile.am had no SUBDIRS entry, so the
  build chain never entered Doc/Illustrations to build
  Catalogue.pdf, even when the project-default target was
  invoked from the root.

  Changes:
    - New Doc/Illustrations/Makefile.am, modelled on
      Models/Makefile.am: lists Catalogue.org, builds PDF
      and HTML using the standard pattern.
    - Doc/Makefile.am adds SUBDIRS = Illustrations plus
      explicit pdf-recursive / html-recursive prerequisites
      on pdf-local / html-local (automake's automatic
      recursion covers all/install/clean/dist but not
      custom targets).
    - configure.ac adds Doc/Illustrations/Makefile to
      AC_CONFIG_FILES.
    - Doc/batch-init.el adds a third component
      bsppfit-doc-illustrations-component to the unified
      bsppfit-all org-publish project; Catalogue.org now
      publishes via the same pipeline as the rest.

  The html-export target's tar invocation is also hardened:
  globs are expanded in a shell loop with empty-match
  warnings rather than direct tar arguments, so a missing
  file class no longer crashes the bundling.

* Honest disclosures

  - The 0.9.3 native-default-form change was unverified by
    execution (no OpenSCAD here). My self-assurance in the
    0.9.3 journal that it would work was wrong; future
    similar reforms should be held until project-author
    execution confirms.
  - The HTML double-row fix is also unverified by execution.
    Setting org-html-home/up-format to "" should suppress
    the legacy nav according to the Org source; if it
    emits an empty wrapper div, a future iteration can
    refine with Emacs advice on org-html-template.

* Phase 1 status

  Per-component:
    Descriptive taxonomy        ~99% (no change in content)
    Illustrations                ~56% (no change)
    Per-size dimension tables   100% (unchanged)
    Validation pass             100% (unchanged)
    BSPP 3D model library       ~15.5% (up from ~15%)

  Weighted Phase 1 aggregate: roughly 65.6% (up from ~65.45%).
  Increment from functional restoration of 0.9.3 features
  that didn't actually work, not new features.


Version 0.9.3 (2026-05-09)
==========================

Polish-and-refinement iteration responding to project-author
review of the 0.9.2 Nipple.scad. Three user-visible improvements,
two infrastructure additions, and several stylistic alignments.

The 2026-05-09 date is an estimate; the project author's
note did not carry an explicit timestamp (in contrast to 0.9.2
which carried [2026-05-08 Fri 10:23]). The project author can
correct in the next iteration if desired.

* User-visible: Nipple defaults reworked

  - middle_shape default changes from "round" to "hex"
    (the commercial norm for brass nipples; round middles
    are uncommon in trade fittings).
  - Parameter list uses OpenSCAD's native default-argument
    resolution: thread_length = bsppfit_useful_thread_length(size),
    middle_od = bsppfit_major_od(size) + 4.0,
    bore = bsppfit_default_bore(size),
    tol_thread = BSPPFIT_TOL_THREAD. The reader sees each
    default at the parameter list rather than having to
    scroll into the body to find the resolution.
  - Each of anchor, spin, orient now has its own
    documentation line listing its default value and
    intended use (the 0.9.2 docstring lumped them under a
    single "passed through transparently" note).

* User-visible: Nipple_Gallery enriched

  Two rows now: hex middle (top) and round middle (bottom),
  both spanning G1/8 through G2. The reader can compare
  shape choice across the size range at a glance.

* User-visible: PDF link in every HTML page's header

  Each rendered HTML page now carries a flex-laid header
  strip at the top: "← Index" on the left (the back-link
  to the project index), "PDF ↓" on the right (a link to
  the same-name PDF in the same directory). End users
  who prefer the PDF rendering can switch with one click
  from any HTML page.

  Implementation: Doc/batch-init.el defines a
  bsppfit/html-preamble function assigned to
  org-html-preamble. It derives the PDF link from the
  current file's basename. The legacy
  org-html-home/up-format is retained as fallback;
  manual export without loading batch-init.el shows the
  stock "UP | HOME" navigation (without the PDF link).

* Infrastructure: html-export Make target

  New target at the project root:

    make html-export

  builds the HTML and PDF versions of every published
  document (Doc/*.org and Models/LibraryOverview.org)
  and bundles them into bsppfit-html-N.N.N.tar.xz at the
  project root. The archive unpacks into a self-named
  subdirectory so deployment doesn't splatter. Suitable
  for direct upload to an HTTP server with scp/rsync.

  Project author confirmed in 0.9.3 review that the
  HTML output served by an HTTP server has working
  internal and external links (orthogonality concern
  from 0.9.1 settled empirically).

* Style: OpenSCAD code style refined

  - /Allman braces, everywhere./ The 0.9.2 addendum
    exempting single-child modifier chains from braces is
    reverted: translate(...) { child; } rather than
    translate(...) child; The standing project rule
    applies without exception to OpenSCAD code.
  - /Hybrid identifier rule./ Public-facing identifiers
    (module names callable from outside the library,
    exported function names, parameters, top-level
    configuration constants) use snake_case for BOSL2
    compatibility. Internal identifiers (local variables,
    private modules/functions prefixed _, internal-only
    constants, loop iterators) use Hungarian notation per
    the standing project rule. The 0.9.2 blanket override
    of Hungarian for OpenSCAD code is replaced.
  - /Whitespace around `=` in named arguments./ The
    standing spaces-around-operators rule extends to
    named-argument syntax: cyl(d = 10, h = 20) rather
    than cyl(d=10, h=20). Applied throughout
    Models/Util/util.scad and Models/G01_Straight/Nipple.scad.
  - /Native default-argument form preferred over
    undef+ternary./ Use OpenSCAD's parameter-list default
    resolution rather than reimplementing it in the body.

  Doc/DevelopmentStandard.org §BSPP Model Library ---
  OpenSCAD Style Addenda rewritten to reflect.

* Honest disclosures

  - Manifold-warning resolution unattributed. The
    NotManifold warning that 0.9.2 review pointed out is
    no longer present in 0.9.3 review, even with
    manifold_safe = false. I cannot pin down which 0.9.2
    change was decisive without rolling back changes one
    by one; the most likely contributor is the
    difference() subtraction of the through-bore.
    Recorded as an honest open item rather than a
    verified attribution.
  - Native default-argument form unverified by OpenSCAD
    execution. I am confident OpenSCAD allows function
    calls in default position and that earlier parameters
    bind for use in later defaults; if an evaluation-
    order quirk breaks this, the next iteration can fall
    back to the body-resolution form.
  - PDF-link feature unverified. The
    bsppfit/html-preamble function follows the documented
    signature; the existing back-link fallback continues
    to render even if the new preamble has a bug.
  - html-export target untested. Standard Make idiom; if
    a glob is empty (e.g. a build that hasn't produced
    PDFs) tar will error.

* Phase 1 status

  Per-component:
    Descriptive taxonomy        ~99% (no change in content)
    Illustrations                ~56% (no change)
    Per-size dimension tables   100% (unchanged)
    Validation pass             100% (unchanged)
    BSPP 3D model library       ~15% (up from ~14%)

  Weighted Phase 1 aggregate: roughly 65.45% (up from ~65.1%).


Version 0.9.2 (2026-05-08)
==========================

Bug-fix-and-modelling-correction iteration responding to
project-author rendering of the 0.9.1 Nipple.scad in OpenSCAD.
Five items addressed: date-format restoration with project-
author-supplied timestamp table, bore-heuristic-verification
convention with cap/plug exception to pipe semantics, residual
manifold warning addressed in two layers, OpenSCAD code style
made explicit (Allman braces with no-brace addendum for
single-child modifier chains), and Models source files
refactored to follow it.

* Project-author timestamp table (canonical)

  The project author has provided a canonical timestamp table
  mapping delivery archives to actual calendar dates. Past
  journal/News/ChangeLog entries with future-dated headings
  generated by the assistant are NOT corrected (per project-
  author direction not to spend tokens on retrofitting), but
  this table is the authoritative source if any retroactive
  reconciliation ever becomes useful:

    Apr 25 14:14  0.1.0
    Apr 25 15:36  0.2.0
    Apr 26 16:37  0.3.0
    Apr 27 14:37  0.4.0
    Apr 29 14:36  0.5.0
    May  2 15:41  0.6.0
    May  2 21:03  0.7.0
    May  3 09:46  0.7.1
    May  3 10:49  0.7.2
    May  3 15:38  0.8.0
    May  3 20:33  0.8.1
    May  3 22:24  0.8.2
    May  4 09:59  0.8.3
    May  4 15:00  0.8.4
    May  5 14:31  0.8.5
    May  5 19:45  0.8.6
    May  6 10:39  0.8.7
    May  6 19:25  0.8.8
    May  7 10:41  0.8.9
    May  7 14:46  0.9.0
    May  7 20:01  0.9.1

  Going forward, dates in headings come from the project
  author's stated request time at the start of each
  iteration (this iteration: 2026-05-08), not from the
  assistant's runtime. Standard NEWS / ChangeLog
  "Version N.N.N (DATE)" / "DATE  Author <email>" formats
  are restored.

* Through-bore for Nipple, with cap/plug exception recorded

  The 0.9.1 Nipple was a threaded rod with no fluid path.
  Fixed: new bore parameter on the public wrapper, defaulting
  to bsppfit_default_bore(size) which returns 0.7 * minor_od
  (commercial-fitting heuristic confirmed against 0.8.8
  catalogue mining: G1/2 nipple gets ~13.0 mm bore, matching
  brass G1/2 nipples in the Ayor/Somatherm range). bore=0
  permitted explicitly, suppressing the through-hole and
  producing a documented "not-a-real-nipple" placeholder
  useful for post-print drilling or visualisation.

  Pipe-semantics convention recorded in LibraryOverview.org
  with the project-author-pointed-out exception: pass-through
  fittings (G-01 straight, G-02 elbow, G-03 tee, G-04 cross,
  G-05 reducer, G-07 union, G-08 hex bushing) need a
  through-bore; terminating fittings (G-06 cap and plug) do
  not; transitional fittings (G-09 hose tail) have a bore on
  the threaded side that opens into a barb-side ID.

  Bore-heuristic-verification convention also recorded: the
  0.7 factor was confirmed for nipples; each new fitting
  must verify the heuristic against trade catalogues for
  that fitting's commercial range and adapt where necessary.

* Manifold warning addressed in two layers

  Layer 1: NIPPLE_MANIFOLD_EPS = 0.01 mm overlap at the seam
  between BOSL2 threaded rods and the middle barrel. Removes
  coplanar-face conditions at the seam.

  Layer 2: new manifold_safe parameter on Nipple, default
  true. When set, BOSL2's bspp_threaded_rod is invoked with
  blunt_start=false, producing simpler bevel-ended thread
  terminations rather than BOSL2's default blunt-start
  lead-in (which has near-zero-thickness facets at the tip
  and is the residual cause of the NotManifold warning the
  project author saw with eps tried up to 1 mm). Users who
  prefer the visually-more-authentic blunt-start render can
  opt in with manifold_safe=false and accept the warning.

  Honest disclosure: this fix is unverified by execution
  (no OpenSCAD in the assistant environment); the reasoning
  relies on BOSL2's source documenting blunt-start as a
  complex thread-end geometry plus the project author's
  report that increasing the seam epsilon alone didn't help.

* OpenSCAD code style explicit, source files refactored

  DevelopmentStandard.org §Algebraic Abstract Languages →
  OpenSCAD Specific Conventions extended with a new
  "BSPP Model Library --- OpenSCAD Style Addenda"
  sub-section recording:
  - Identifier-style override for code under Models/:
    snake_case for functions and module parameters,
    UPPERCASE_SNAKE_CASE for global constants, modules
    remain PascalCase (project naming convention),
    private modules/functions prefixed with _.
    Overrides the project's standing Hungarian rule for
    OpenSCAD code in this directory because the library
    targets potential downstream BOSL2 contribution.
  - Brace-style addendum: single-child modifier chains
    (translate, rotate, scale, mirror, color, up, down,
    left, right, fwd, back, xrot, yrot, zrot) use NO
    braces; the child appears on the next line, indented.
    Multi-child compounds (union, difference, intersection,
    hull, etc.) use Allman braces per the parent rule
    (opening brace alone on its own line, aligned under
    the introducing statement).

  Models/Util/util.scad and Models/G01_Straight/Nipple.scad
  refactored throughout to follow the new addenda. Same
  conventions documented in LibraryOverview.org §Conventions
  for visibility from the model library entry point.

* Phase 1 status

  Per-component:
    Descriptive taxonomy        ~99% (no change in content)
    Illustrations                ~56% (no change)
    Per-size dimension tables   100% (unchanged)
    Validation pass             100% (unchanged)
    BSPP 3D model library       ~14% (up from ~13%)

  Weighted Phase 1 aggregate: roughly 65.1% (up from ~64.75%).
  Modest correctness-driven increment again.


Version 0.9.1 (2026-05-11)
==========================

Bug-fix-and-cleanup iteration responding to project-author
review of the 0.9.0 model-library bootstrap. Four items:
util.scad runtime bug fix, API change to numeric size keys,
README.org rename and PDF/HTML build integration, unified
publish project for cross-document anchor resolution.

* util.scad search() bug fix

  The 0.9.0 bsppfit_lookup() used search() with an incompatible
  combination of arguments (listful first arg + index_col_num),
  producing a runtime failure on every model invocation:

    WARNING: len() parameter could not be converted: argument 0:
      expected string, found number (3) ...
    ERROR: Assertion '!is_undef(row)' failed: "bsppfit: unknown
      BSPP designator 'G1/2'." ...

  The 0.9.1 form follows BOSL2's own pattern for table lookups
  (search(value, table-of-rows)) and works correctly.

* Numeric size keys (API change)

  Per project-author direction, the model API now uses numeric
  fractional-inch size keys rather than "G..."-prefixed strings:

    Nipple(size=1/2)        instead of Nipple(size="G1/2")
    Nipple(size=1+1/4)      instead of Nipple(size="G1 1/4")
    Nipple(size=2)          instead of Nipple(size="G2")

  Rationale: the "G" prefix is redundant inside a BSPP-only
  library; numeric keys compose more cleanly with BOSL2's
  bspp_threaded_rod() (which expects exactly this form); and
  the project author's BSPP-threading collaborator preferred
  numerics.

  The "G..."-prefixed designator is kept as a human-readable
  label: Util/dimensions.csv has it as a column,
  Util/util.scad's bsppfit_designator(size) returns it for
  warning messages and gallery labels.

  Affected files:
  - Util/dimensions.csv: column order changed (size_inches
    first as primary key, designator second).
  - Util/util.scad: BSPP_TABLE matches the new column order;
    bsppfit_size_inches() removed (no longer needed; size IS
    the inches value); accessor functions accept numeric size;
    bsppfit_designator(size) added; bsppfit_sizes() added.
  - G01_Straight/Nipple.scad: default size=1/2, examples
    updated, gallery iterates bsppfit_sizes() not designators.

* README.org renamed to LibraryOverview.org

  The project's PascalCase-and-descriptive filename convention
  used throughout Doc/ called for a more specific name than the
  generic README.org. LibraryOverview.org is PascalCase and
  immediately reads as "what this file describes".

  Same change brings the file into the standard PDF/HTML build
  pipeline. Models/Makefile.am now mirrors Doc/Makefile.am with
  DOC_FILES = LibraryOverview.org and the standard
  %.pdf : %.org pattern rule and html.stamp target. The
  preamble follows the Doc/ template:
    #+INCLUDE: ../Doc/version.org
    #+LATEX_HEADER: \input{../Doc/Preamble.tex}
    #+LATEX_HEADER: \svnInfo $Id$
    #+EXPORT_FILE_NAME: LibraryOverview.pdf
  --- the same relative-path pattern that
  Doc/Illustrations/Catalogue.org already uses.

  Linked from Doc/Index.org under a new "Model library"
  section.

* Unified HTML publish project (cross-document anchor resolution)

  Doc/batch-init.el's org-publish-project-alist extended with
  three additional entries activated when the BSPPFIT_TOP_SRCDIR
  environment variable is set:

  - bsppfit-doc-component       (rooted at Doc/)
  - bsppfit-models-component    (rooted at Models/)
  - bsppfit-all                 (aggregate :components of both)

  bsppfit/publish-all checks the env var and publishes the
  unified bsppfit-all project under autotools-driven Make
  builds. Without the env var (interactive Emacs use from a
  single directory), the legacy bsppfit-docs project is used,
  preserving 0.9.0 behaviour exactly.

  Effect: cross-document file: links between Doc/* and
  Models/LibraryOverview.org (in either direction) get full
  anchor resolution under "make html", avoiding the "cannot
  resolve without publishing" warnings on the cross-directory
  links. The .org -> .html URL rewriting was already automatic
  via org-html-link-org-files-as-html and works under HTTP
  serving as long as the .html files are served alongside.

  Doc/Makefile.am and Models/Makefile.am both pass
  BSPPFIT_TOP_SRCDIR='$(top_srcdir)' to the Emacs invocation.

* Phase 1 status

  Per-component:
    Descriptive taxonomy        ~99% (no change in content)
    Illustrations                ~56% (no change)
    Per-size dimension tables   100% (unchanged)
    Validation pass             100% (unchanged)
    BSPP 3D model library       ~13% (up from ~12%)

  Weighted Phase 1 aggregate: roughly 64.75% (up from ~64.4%).

  Modest increment; the iteration's value is correctness rather
  than addition. The 0.9.0 bootstrap claim of "architecture
  demonstrated end-to-end" was strictly incorrect until 0.9.1
  fixed the search() bug, so the architecture-credit bump from
  ~12% to ~13% reflects what is now actually true.

* Honest disclosures

  - The 0.9.0 bootstrap was not validated by execution. The
    fix is mechanical but the lesson is that "writes
    correctly" and "executes correctly" are different
    claims.
  - The Models-publish-project elisp addition follows
    documented Org-publish conventions but was not
    validated by running the Emacs build. The unset-env-var
    fallback restores 0.9.0 behaviour exactly if the new
    code paths misbehave.


Version 0.9.0 (2026-05-10)
==========================

Minor-version bump marking the opening of the BSPP 3D model
library, the third Phase 1 deliverable. The transition is
substantive: the project now contains OpenSCAD source under
Models/ in addition to the Org documentation under Doc/.

Headline change: Models/G01_Straight/Nipple.scad implements a
BSPP nipple end-to-end, exercising every architectural decision
recorded in Concept.org §Modelling Approach for the BSPP Model
Library. With this pilot in place, adding the remaining
geometry classes is template-and-adapt rather than design.

* Models/ tree opened

  New project-root directory parallel to Doc/. Initial contents:

  - Models/README.org: library overview, folder layout, and
    conventions documentation.
  - Models/Util/dimensions.csv: source of truth for the BSPP
    per-size table. Mirrors tab:bspp-dimensions in Taxonomy.org,
    9-row common-fittings range G1/8 through G2.
  - Models/Util/util.scad: OpenSCAD helpers. BSPP_TABLE
    constant mirroring the CSV, lookup functions
    (bsppfit_lookup, bsppfit_size_inches, bsppfit_major_od,
    etc.), tolerance defaults (BSPPFIT_TOL_THREAD,
    BSPPFIT_TOL_GASKET, BSPPFIT_TOL_FACE, BSPPFIT_TOL_PIPE),
    self-correcting middle-OD helper (bsppfit_safe_middle_od),
    designator enumeration, and an echo-only self-test module.
  - Models/G01_Straight/Nipple.scad: pilot model. BSPP nipple,
    male x male, round or hex barrel. Wrapper Nipple() with
    underscore-implementation _nipple(), designator-keyed size
    parameter, BOSL2's bspp_threaded_rod as the threading
    layer, attachment-system pass-through (anchor, spin,
    orient), multi-named tolerance support, self-correcting
    middle-OD, gallery module Nipple_Gallery(), and a test-area
    toggle at the bottom of the file per the doommeister-
    derived 0.8.3 architecture extension.
  - Models/Makefile.am: stub Makefile registering the model
    files in EXTRA_DIST and providing a placeholder render
    target.

* Build-system registration

  Makefile.am (root): SUBDIRS extended from "Doc" to
  "Doc Models". The forward-looking comment that previously
  said "SUBDIRS list will grow at that point" is replaced with
  a comment noting that the library opened in 0.9.0.

  configure.ac: AC_CONFIG_FILES extended to generate
  Models/Makefile from Models/Makefile.am. Without this entry,
  ./configure would not produce a Models/Makefile and "make
  dist" would not include the model sources.

* What is not in 0.9.0

  Eight of the nine geometry classes (G02_Elbow, G03_Tee,
  G04_Cross, G05_Reducer, G06_CapPlug, G07_Union, G08_HexBush,
  G09_HoseTail) are queued for following iterations. Each new
  fitting is now template-and-adapt from the Nipple file, in
  the order suggested by validation-scenario demand and domain
  frequency.

  Female and mixed-gender variants of the nipple are also
  queued: 0.9.0 ships M x M only. The architecture decision
  (single module per fitting with gender= parameter) is
  preserved as next-iteration work for this file, not yet
  exercised.

  Render pipeline (make render in Models/Makefile.am) is a
  placeholder. Producing reference PNGs requires OpenSCAD in
  the build chain; deferring until several models exist avoids
  per-iteration toolchain churn.

* Phase 1 status

  Per-component:
    Descriptive taxonomy        ~99% (no change in content)
    Illustrations                ~56% (no change)
    Per-size dimension tables   100% (unchanged)
    Validation pass             100% (unchanged)
    BSPP 3D model library        ~12% (up from ~7%)

  Weighted Phase 1 aggregate: roughly 64.4% (up from ~62.7%).

  Reasoning for the model-library percentage is recorded in
  the iteration journal entry: ~50% of the bucket is
  architecture (now ~95% complete; one decision still open),
  ~10% is bootstrap (now done), ~40% is per-fitting modelling
  (1/9 of geometry classes started, ~1/3 of within-class
  variants, so ~4% of the library figure).


Version 0.8.9 (2026-05-09)
==========================

Quality-and-correction iteration. Two FutureResearch items
closed: verbatim-aware mode for the cross-reference scripts,
and HTML Index back-link orthogonality between manual and
batch export. BOSL2 source briefly inspected for next-session
preparation; not acted on this iteration.

* HTML Index back-link orthogonality

  The 0.8.8 approach used per-file #+HTML_PREAMBLE and
  #+HTML_POSTAMBLE keywords on Doc/Illustrations/Catalogue.org
  to override the global postamble. This worked for the batch
  export path (when Doc/batch-init.el is loaded) but failed
  for the manual export path (interactive Emacs export
  without batch-init.el).

  The 0.8.9 approach uses Org's universally-supported
  #+HTML_LINK_UP and #+HTML_LINK_HOME keywords on every
  document except Doc/Index.org. Both keywords point at
  Index.html (relative or ../Index.html for the
  sub-directory Catalogue). Org's standard machinery
  generates a home/up navigation block at the top of the
  body, formatted via org-html-home/up-format.

  Doc/batch-init.el simplified: removed the custom
  org-html-preamble and org-html-postamble strings. Org's
  default 'auto postamble handles author and date display
  in both export paths. A custom org-html-home/up-format
  in batch-init.el renders the back-link as "← Index"
  rather than the default "UP | HOME"; manual export
  shows the default rendering, with both links pointing
  at Index.

* Verbatim-aware mode for cross-reference scripts

  bin/checkxref and bin/applyxref gain a --verbatim-aware
  flag. When set, they flag (or fix) ~Term~ verbatim
  spans whose entire content is a defined term, wrapping
  them as [[anchor][~Term~]]. Two heuristic exceptions
  prevent false positives:

  - Verbatim subjects of definition-list items (`- ~X~
    :: BODY`), as in SC-09's token-by-token marking
    breakdown.
  - Verbatims in the first cell of a table row (`| ~X~ |
    description |`), as in F-07's tab:fitting-markings
    table.

  Both exceptions are forms of the existing rule
  exception (c) "table/list of the term itself".

  Verification on Taxonomy 0.8.8 surfaced 7 candidates;
  after the (e2) heuristic, 4 real defects remained, all
  fixed by bin/applyxref --verbatim-aware. Zero defects
  in both default and verbatim-aware mode after the run.

  Documentation in DevelopmentStandard.org §Cross-
  Referencing Defined Terms updated with the verbatim-
  wrapping rule and its exceptions.

* Note on BOSL2 source (informative)

  The project author uploaded BOSL2-master.zip for the
  next session. CLAUDE.md briefly inspected; key
  conventions (entry point std.scad, attachment system,
  VNF, dual function/module pattern, include guards,
  4-space indent, test pattern, naming convention)
  recorded in the iteration journal entry for ready
  reference next session. /Not adopted this iteration./
  BSPPFit standards take precedence over BOSL2's; BOSL2
  is informative.


Version 0.8.8 (2026-05-08)
==========================

Quality-and-correction iteration responding to project-author
review of the 0.8.7 delivery. Per-size dimension tables aligned
to a common range; HTML back-link to Index now works from the
sub-directory Catalogue document; HTML postamble extended to
display author and date "the same way as the PDF"; four
bilingual additions and one new glossary entry derived from
project-author-supplied French supplier catalogues.

* Per-size dimension table alignment

  All four sizing tables in F-04 (BSPP size equivalence, BSPP
  per-size, BSPT per-size, NPT per-size) now have the same 9
  rows covering the common-fittings range G1/8 -- G2 (and
  thread-form equivalents).

  Trimmed from BSPP per-size: G1/16, G5/8, G7/8, G2 1/2, G3.
  Trimmed from BSPT per-size: R1/16.
  Trimmed from NPT per-size: 1/16 NPT.

  Captions on the three per-size tables updated to point
  readers to ISO 228-1 / ISO 7-1 / ANSI/ASME B1.20.1 for sizes
  outside the table range.

* HTML Catalogue back-link to Index

  Doc/Illustrations/Catalogue.org gained per-file
  #+HTML_PREAMBLE and #+HTML_POSTAMBLE overrides that point at
  ../Index.html (one level up). The global postamble in
  Doc/batch-init.el keeps the simple "Index.html" target for
  documents in Doc/.

* HTML author and date in postamble

  Doc/batch-init.el's org-html-postamble extended to include
  the author (%a from #+AUTHOR) and the export timestamp (%T)
  alongside the back-link. Matches the visible author/date
  block in the PDF (LaTeX) export.

  The %T format specifier is used rather than %d because no
  project document carries an explicit #+DATE; %T always
  produces a value at export time (matching LaTeX's \today
  behaviour for missing dates).

* Bilingual additions from supplier-catalogue mining

  Project author uploaded 14 PDFs from Comisa (Italian
  trilingual export labels) and Ayor/Somatherm (French
  distributor). Mining yielded:

  - tab:bilingual-gender: AG = Außengewinde / IG =
    Innengewinde German shorthand documented in the table
    caption and Notes columns of the Female / Male / Mixed
    rows.

  - tab:bilingual-geometry: three new rows --- Extension
    nipple (rallonge / Hahnverlängerung), Swivel nut (écrou
    prisonnier / Gelenkmutter), Wallplate elbow (coude
    applique / Wandwinkel). The Plug row gained "German:
    Stopfen" in its Notes.

  - tab:bilingual-approvals: new row for DVGW W 534, German
    potable-water approval for metallic fittings.

  - Glossary: new entry term-dvgw-w534 explaining that DVGW
    W 534 is finer-grained than KTW (specifically for
    metallic and combination drinking-water fittings).

  - F-08 Plumbing (potable water) context paragraph extended
    to mention DVGW W 534 alongside WRAS / ACS / KTW.


Version 0.8.7 (2026-05-07)
==========================

Quality-and-correction iteration responding to project-author
review of the 0.8.6 delivery. Substantive corrections in
several places: cross-referencing rule scope clarified;
bilingual sizing note rewritten honestly (a fabricated
"15/21 family" label retracted, "Imperial" column header
replaced with "BSPP designator", DN as separate column, German
practice explained); Elbow glossary entry extended with LR/SR
domain and materials information; Introduction broken link
fixed and meta-process paragraphs removed; sections reordered
so Glossary and Bilingual Labels are the document's last
reference sections; HTML back-link to Index added.

* Cross-referencing rule scope clarified

  Project author specified that only Doc/Taxonomy.org is in
  scope fully; Doc/ResearchJournal.org and
  Doc/FutureResearch.org are in scope only for passages
  discussing taxonomy or modelling content with specific
  trade terms; Doc/DevelopmentStandard.org,
  Doc/Constitution.org, Doc/Concept.org,
  Doc/Illustrations/Catalogue.org, and Doc/Index.org are
  entirely out of scope.

  DevelopmentStandard.org §Cross-Referencing Defined Terms
  revised with explicit /In scope --- full rule applies/ and
  /Out of scope --- rule does not apply/ lists. Rule 2
  simplified accordingly.

  The 0.8.6 "Cross-reference audit on non-Taxonomy
  documents" TODO is marked DISMISSED with rationale: most
  of its planned-audit-target documents are out of scope
  under the clarification.

* bin/applyxref shipped

  Moved from the assistant's working tree into the project
  tree at bin/applyxref. Companion to bin/checkxref: where
  checkxref reports defects, applyxref rewrites source
  files to apply the every-occurrence rule (with the four
  documented exceptions). Added to EXTRA_DIST.

  Naming: lowercase single word, no hyphen, no extension,
  per DevelopmentStandard.org §Naming Convention Scope.

* Bilingual sizing note rewritten

  - "The 15/21 family" label retracted. Verified against
    multiple French commercial sources that the trade
    vocabulary is "norme", "dimension", "format",
    "désignation métrique", "appellation française" --- never
    "famille". The label was a project-internal coinage; it
    is removed from the bilingual section and from two
    residual mentions in the coverage map.

  - "Imperial" column header replaced with "BSPP
    designator". The G-prefix is the ISO 228 metric
    standard; "Imperial" was historically defensible but
    now misleading.

  - Three coexisting designation systems made explicit:
    BSPP G-designator (universal, e.g. G1/2), European DN
    code (ISO 6708, e.g. DN 15), French DI×DE designation
    (metropolitan-French specifically, e.g. 15 × 21).

  - German practice answered. German catalogues typically
    print three labels on the same fitting: G 1/2 Zoll, DN
    15, 1/2"AG (where AG = Außengewinde). The /15 × 21/
    DI×DE form is rare in German commercial use.

  - Misleading "G1/2 is BSPP half inch" cell content
    corrected to a neutral row pointing to F-04 for the
    bore-vs-OD discussion.

* Elbow glossary entry extended

  - LR/SR distinction now records the materials and
    domain partition: SR for pressurised systems
    (BSPP-territory default); LR for low-pressure
    gravity-fed (DWV, sewage, central vacuum) typically
    in ABS/PVC/CPVC/copper. Source: project-author-
    supplied Wikipedia text.

  - Implication for BSPPFit recorded: LR/SR is a
    /property of an elbow/ rather than a separate facet
    axis. The facet question is deferred to the Facet
    audit against ISO 12006-2 / UniClass 2015, which is
    more likely to surface other length and curvature
    facets together.

* Taxonomy.org Introduction cleaned

  - Broken link to journal scope decision fixed via stable
    anchor in Doc/ResearchJournal.org.

  - Two meta-process paragraphs removed (scaffolding from
    early iterations: "at the iteration first opened...
    iteration 0.4.0 fleshes out... captions and #+NAME:
    anchors per the Development Standard...").

* Section ordering

  Coverage map → Glossary → Bilingual Labels → Sources and
  Attributions. The glossary and bilingual labels are now
  the document's reference back-matter; the eventual Index
  will slot in alongside them. Coverage map sits between
  the substantive content and the back-matter, matching
  its role as positioning vis-à-vis Wikipedia rather than
  reference lookup.

* HTML back-link to Index

  Wired in Doc/batch-init.el via org-html-preamble and
  org-html-postamble. Every document except Index.html
  itself gets a small "← Index" link at top and bottom.
  Index.org overrides via #+OPTIONS html-preamble:nil
  html-postamble:nil to avoid linking to itself.

* HTML list of tables

  Added to Doc/Taxonomy.org via #+TOC: tables in a
  collapsible <details> block. The PDF list-of-tables
  continues to come from the existing #+LATEX:
  \listoftables directive.

  /HTML list of figures/ requires custom elisp (Org-mode's
  HTML export does not have a native #+TOC: figures
  directive). Tracked as a TODO in FutureResearch.org with
  three implementation candidates.

* Approval-term cross-references in SC-06

  ~WRAS~, ~ACS~, ~KTW~ in SC-06's resolution paragraph
  manually wrapped as [[term-wras][~WRAS~]] etc. (link
  wrapping verbatim, not instead of). The
  bin/checkxref verbatim-exemption skipped these; a
  /verbatim-aware mode/ refinement to bin/checkxref and
  bin/applyxref is tracked as a TODO so future
  occurrences are caught automatically.

* Phase 1 completion status (iteration 0.8.7)

  Per-component:
    Descriptive taxonomy        ~98.5% (up from ~98%)
    Illustrations                ~56% (no change)
    Per-size dimension tables   100% (unchanged)
    Validation pass             100% (unchanged)
    BSPP 3D model library         7% (no change in code)

  Weighted Phase 1 aggregate: roughly 62.5% (up from ~62.3%).


Version 0.8.6 (2026-05-06)
==========================

Substantive iteration: the descriptive-taxonomy
cross-reference audit completes on Doc/Taxonomy.org, the
verification script bin/checkxref ships, and a heating-
engineer trade-specialist correction lands as a substantive
F-08 regional note.

* bin/checkxref verification script

  Python 3 script enumerating <<term-X>> anchors and reporting
  body occurrences not preceded by a link, with the four
  exceptions from DevelopmentStandard.org §Cross-Referencing
  Defined Terms applied. Modes: default verbose, --brief
  (grep-friendly one-line), --summary (per-term defect counts),
  --include-mass (override the grammatical-mass exclusion).

  Wired via the project root Makefile.am check-xref target;
  ships in EXTRA_DIST.

* Cross-reference audit on Doc/Taxonomy.org

  354 link-additions in two passes:
    First pass (excluding BSPP/BSPT/NPT trio): 249
    Second pass (BSPP/BSPT/NPT trio): 105

  Post-audit checkxref output: zero defects under the rule's
  four exceptions.

  Three design refinements emerged from running the audit:

  - Grammatical-mass exception added as the rule's fourth
    exception. Initial list: Fitting, Port, Male, Female. A
    term joins the list when an audit pass shows visible
    saturation; a term leaves it when a future audit shows
    the saturation was over-cautious. Decisions are
    documented as journal entries.

  - Document-role distinction added. The reader-entry
    document (Doc/Taxonomy.org) follows the every-occurrence
    rule. Other documents (Concept, Research Journal, Future
    Research, Development Standard, Catalogue, Index) follow
    the lighter first-occurrence-per-section rule, on the
    rationale that they are read linearly within a section
    rather than entered randomly.

  - Hyphen-in-word-boundary technical fix. Standard regex
    \b matches at hyphens, causing false matches like
    "cross" in "cross-reference". The script uses a stricter
    boundary that excludes hyphens and underscores.

* Bilingual /pas du gaz américain/ resolved by trade-specialist

  Project author obtained heating-engineer (France) input on
  the open question. Resolution:

  - Metropolitan-French trade term is /filetage américain/,
    not /pas du gaz américain/.
  - /filetage américain/ is used in limited situations,
    not for gas service.
  - Gas service in metropolitan-French domestic plumbing
    uses BSPP with a flat gasket.

  Two distinct landings:

  - Bilingual table cell for the Sellers thread profile
    row updated: parenthetical /(pas du gaz américain) [à
    vérifier]/ replaced with /filetage américain/, with
    a usage note in the Notes column.

  - F-08 Gas application context extended with a /Regional
    note --- French metropolitan domestic practice/
    subsection. The European-default claim (BSPT favoured;
    BSPP soft-elastomer face seal acceptable in some
    low-pressure appliance connections) stands; the
    regional note records that French metropolitan domestic
    practice diverges, using BSPP-with-flat-gasket as the
    primary convention. Other regional variations may
    surface; tracked in the rolling list.

* Cross-Referencing Defined Terms rule (DevelopmentStandard.org)

  Updated to reflect 0.8.6 discoveries:

  - Five operational rules instead of four (rule 2 split
    into "linking density depends on document role" and rule
    3 expanded with the four exceptions).

  - Explicit grammatical-mass terms table (Fitting, Port,
    Male, Female) with rationale for current membership and
    procedure for adding/removing terms.

  - Decision narrative recording how the document-role
    distinction was discovered through the audit, with
    cross-reference to the iteration 0.8.6 journal entry.

* Future Research updates

  - Retroactive cross-reference audit (body of Taxonomy.org):
    closed (DONE) with closure note recording the 354
    link-additions, the verification-script output, and the
    three design refinements that emerged.

  - Cross-reference verification script: closed (DONE) with
    closure note recording the script's behaviour and the
    Makefile wiring.

  - New TODO "Cross-reference audit on non-Taxonomy
    documents": the lighter-density audit for Concept,
    Research Journal (with append-only constraint), Future
    Research, Development Standard, Catalogue, and Index.

* Phase 1 completion status (iteration 0.8.6)

  Per-component:
    Descriptive taxonomy        ~98% (up from ~97%)
    Illustrations                ~56% (no change)
    Per-size dimension tables   100% (unchanged)
    Validation pass             100% (unchanged)
    BSPP 3D model library         7% (no change in code)

  Weighted Phase 1 aggregate: roughly 62.3% (up from ~61.7%).


Version 0.8.5 (2026-05-05)
==========================

Quality-and-correction iteration responding to seven
project-author corrections from 0.8.4. The architectural
substance is unchanged; the iteration value is in correctness:
honest reconsideration of the cross-referencing rule, migration
of the decisions-awaiting list to its proper home, fixes to
underscore-rendering defects, closure of two pending
borrow-from-Wikipedia candidates, and confirmation of
BOSL2-integration as the long-term goal with deferred timing.

* Cross-referencing rule reconsidered honestly

  The 0.8.4 rule asserted "Chicago + ISO + IBM converge on
  first-occurrence-per-section linking". The project author
  challenged this. Re-checking the sources in 0.8.5:

  - Chicago Manual of Style §10.2 covers first-occurrence
    parenthetical expansion of abbreviations, not body-to-
    glossary linking density.
  - Chicago §16 covers cross-references within an index,
    not body-to-glossary.
  - ISO/IEC Directives Part 2 prescribes typographic
    distinguishability of defined terms, not hyperlink
    density.
  - Microsoft and IBM style guides do not have a published
    rule on hyperlink density that I could cite.
  - Wikipedia WP:OVERLINK and DITA community discussions
    lean toward "once is enough" with carve-outs.

  No consensus exists. The 0.8.4 framing was overconfident.

  The revised rule in DevelopmentStandard.org §Cross-
  Referencing Defined Terms acknowledges two competing
  principles (reader-entry vs visual-clutter) and adopts
  the reader-entry principle for BSPPFit on the basis that
  the documentation is consulted non-linearly. The
  operational rule: every occurrence of a defined term in
  prose links to the canonical anchor, with three documented
  exceptions: (a) the definition itself; (b) successive uses
  in the same paragraph; (c) tables of the term itself.

* Decisions-awaiting list migrated to FutureResearch

  The rolling list of open decisions was created in 0.8.4 in
  the Research Journal. The project author corrected the
  placement in 0.8.5: per the temporal-triad convention
  (Concept = present, Journal = past, FutureResearch =
  future), open decisions belong in FutureResearch.

  The list is now at FutureResearch.org §Decisions awaiting
  project-author input (rolling list). The journal stub at
  the original creation date preserves the pointer.

  Convention going forward: open decisions live in
  FutureResearch as the rolling list; resolved decisions
  migrate to the Research Journal as one-line resolution
  events dated to the iteration of resolution.

* Underscore-protection audit (13 defects fixed)

  The 0.8.4 review showed that ~snake_case~ in prose was
  rendering as /snake/-with-/case/-as-subscript in the LaTeX
  export, in violation of DevelopmentStandard §4.3.5. An
  audit of all .org files for unprotected underscores in
  identifier-like words in prose found 13 real defects:

    Concept.org:           NPT_Library, snake_case
    DevelopmentStandard:   old_function
    FutureResearch.org:    BSP_thread_form.SCAD,
                           NPT_Library,
                           PERMISSIONS_ERROR
    ResearchJournal.org:   EXTRA_DIST,
                           NPT_Library,
                           PERMISSIONS_ERROR,
                           snake_case (×2),
                           thread_profile,
                           web_fetch

  All 13 fixed by wrapping in ~...~ verbatim per the
  documented rule. Re-audit confirms zero remaining defects.

* Borrow-from-Wikipedia candidates: two more closed

  Per project-author direction in 0.8.5:

  - Street elbow: adopted as a mixed-gender F-02 value on
    F-01 elbow (NOT as a separate F-01 sub-type). New
    glossary entry term-elbow-street records the shape:
    F-01 Elbow + F-02 Mixed-gender in the faceted model.

  - Close nipple: adopted as a length sub-variant of
    /Nipple/. New glossary entry term-nipple-close. The
    parent Nipple entry was extended to record that
    standard nipples are male-only by definition.

  An open question raised by the project author: are there
  male AND female nipples, or specifically close nipples?
  Tracked as an open item in the rolling list pending
  trade-specialist input. The candidate answer the assistant
  could reach from documentary sources (Wikipedia,
  HardHatEngineer, FreshWaterSystems): nipples are male-only
  by definition; female-female straight fittings are
  couplings or sockets; close nipples are length-variants of
  male nipples. Needs trade-specialist confirmation.

  The remaining LR/SR-as-separate-facet candidate is
  deferred per project-author direction.

* BOSL2 integration confirmed as long-term goal

  Project author in 0.8.5: BOSL2 integration is the
  long-term goal. Recorded as a settled commitment in
  Concept.org §Modelling Approach.

  Timing: project author chose not to upload BOSL2 source
  in this iteration to prevent precipitation into
  model-library implementation before the descriptive
  taxonomy is finalised. The descriptive-taxonomy
  finalisation gate is the cross-reference audit (helps
  with illustrations).

* Cross-reference verification script: naming corrected,
  Makefile rule added

  - Script naming corrected from bin/check-cross-refs to
    bin/checkxref per DevelopmentStandard.org §Naming
    Convention Scope §2.2.1 (lowercase single word, no
    extension, no hyphen).

  - New Makefile target check-xref in the project root
    Makefile.am. The target detects the script's absence
    and exits with a "not yet implemented" message, since
    the script itself remains a TODO. Once the script
    lands, the rule executes it directly.

* New TODO: Index for the Taxonomy document

  Filed in FutureResearch.org with state-of-the-art
  thresholds for when reference-style technical documents
  warrant an index:

    - Chicago Manual §16: ~100 pages
    - American Society for Indexing: 50 pages benefit /
      100 pages should
    - Reference works: regardless of length
    - ISO 999:1996 prescribes how, not when
    - Tom Mulvany Indexing Books (U. Chicago Press)
      reaffirms 50/100 with reference-work carve-out

  The Taxonomy document is reference-style and crosses the
  50-page threshold in PDF, so it qualifies on both
  type-of-work and size dimensions. Trigger to action:
  taxonomy stops accumulating new structural extensions for
  two consecutive substantive iterations AND the cross-
  reference audit has closed.

* Phase 1 completion status (iteration 0.8.5)

  Per-component:
    Descriptive taxonomy        ~97% (up from ~96.5%)
    Illustrations                ~56% (no change)
    Per-size dimension tables   100% (unchanged)
    Validation pass             100% (unchanged)
    BSPP 3D model library         7% (no change in code)

  Weighted Phase 1 aggregate: roughly 61.7% (up from ~61.5%).


Version 0.8.4 (2026-05-04)
==========================

Quality-and-correction iteration. The substance: one new
illustration (I-09 Sellers historical thread-form plate),
several new glossary entries, the bilingual section
cross-referenced to glossary anchors. The structural work
is larger: the Concept document's "Modelling Approach for
the BSPP Model Library" section refactored from a 460-line
decision-record into an 87-line summary table that
cross-references the Research Journal where the decisions
properly live; a new Cross-Referencing Defined Terms rule
in DevelopmentStandard.org with Chicago-Manual-derived
five-rule standard; retraction of the 0.8.3 "minority
pattern" framing on gender handling.

* Concept refactor (Constitution alignment)

  - Doc/Concept.org "Modelling Approach for the BSPP Model
    Library" section: refactored from 460 lines to 87 lines.
    Old form was a decision-record (alternatives + decision
    + rationale per architectural choice); per the
    Constitution, decision records belong in the Research
    Journal. New form is a summary table of architectural
    choices with cross-references to the journal entries
    that record /why/. Decision content is preserved (in
    the journal); the Concept document now describes the
    project's evolving conceptual state without duplicating
    decision history.

  - New section in the Concept summary table: BOSL2-
    integration goal noted as a possible long-term goal
    raised by the project author. If pursued, the
    architecture acquires conformance-to-BOSL2 as a hard
    constraint (snake_case naming, attachable() anchor
    system, BOSL2 in-source documentation format,
    orthogonality with existing BOSL2 modules). Tuning
    deferred to the next iteration once BOSL2 source is
    fully visible to the assistant.

* Cross-referencing rule established

  - Doc/DevelopmentStandard.org: new section
    "Cross-Referencing Defined Terms" added. Five-rule
    standard derived from Chicago Manual of Style §2.36 +
    §14, ISO/IEC Directives Part 2, and Microsoft and IBM
    style guides:
      1. Every defined term has exactly one canonical
         anchor.
      2. First occurrence per top-level section links to
         the canonical anchor.
      3. Inter-glossary references are bidirectional.
      4. Cross-language equivalents link to the canonical
         anchor in both directions.
      5. Defects are findable mechanically (verification
         script tracked as a TODO in FutureResearch).

* Bilingual section cross-references fixed

  - Doc/Taxonomy.org bilingual section: 65 row-level
    updates linking both the English and French columns
    to the term anchor. A French-→English-→glossary lookup
    is now one click from definition.

  - 52 new <<term-X>> anchors added to glossary entries
    that previously lacked them.

  - 7 new glossary entries added to fill cross-reference
    gaps surfaced by the bilingual table:
      Cap, Coupling, Cross, Elbow (with Wikipedia
      borrow-candidates: 22.5° angle, LR vs SR
      distinction, plumbing-vs-protractor angle
      clarification), Fitting (generic), Plug, Port,
      Sellers profile (paired with Whitworth profile),
      Tee, Wye.

* I-09 Sellers historical thread-form plate

  - Doc/Illustrations/ThreeThreadForms.png placed
    (William Sellers 1864 paper, public domain via
    Wikimedia Commons; supplied by the project author).

  - Embedded in F-03 Comparison subsection of the
    Taxonomy with informational caveat (the plate is
    1864 and pre-dates modern dimensional standards;
    reproduced for visual comparison only). Together
    with the I-01 Whitworth SVG, this addresses most
    of the original I-01 ambition for a side-by-side
    comparison.

  - I-09 row added to Sources and Attributions table
    in Taxonomy.org and to the Illustrations Catalogue
    Index plus a per-slot DONE record.

* Gender-handling decision: framing corrected, choice unchanged

  - The 0.8.3 journal entry framed BSPPFit's
    single-module-with-gender-parameter choice as
    "minority pattern in the surveyed set, not
    consensus". The framing was wrong epistemology: the
    taxonomy is the source of truth for API shape, and
    surveyed-library counts are not votes. Retracted in
    a new journal entry that records the deeper rule:
    /derive the API from the taxonomy first; consult
    surveyed libraries for considerations and
    comparisons, not for votes/.

  - The architectural choice itself is unchanged. What
    changes is the justification: justified by the
    taxonomy, period; not justified by an appeal to
    majority that needed to be defended against.

* Decisions awaiting project-author input (rolling list)

  - New journal entry consolidates the open decisions
    that the assistant has surfaced and is waiting on.
    Currently open: BOSL2 conformance and integration
    goal (needs source visibility); bilingual
    [a verifier] items; remaining borrow-from-Wikipedia
    candidates (street elbow, close nipple, LR/SR as
    separate facet); first concrete model-library file
    (depends on BOSL2 question); Facet audit timing
    against ISO 12006-2 / UniClass 2015.

  - Refresh convention: each iteration updates this
    rolling-list entry in place; resolved items move to
    a Recently-closed sub-section. This is a
    documented deviation from the journal's
    append-only convention; project author may
    override.

* Two new TODOs in FutureResearch

  - Retroactive cross-reference audit: links
    first-occurrence-per-section in the body of
    Taxonomy.org outside the glossary and bilingual
    section. Driven by the verification script.

  - Cross-reference verification script:
    bin/check-cross-refs shell script that produces a
    defect report driving the audit.

* Phase 1 completion status (iteration 0.8.4)

  Per-component:
    Descriptive taxonomy        ~96.5% (up from ~96%)
    Illustrations                ~56% (up from ~50%)
    Per-size dimension tables   100% (unchanged)
    Validation pass             100% (unchanged)
    BSPP 3D model library         7% (no change in code)

  Weighted Phase 1 aggregate: roughly 61.5% (up from ~60.5%).


Version 0.8.3 (2026-05-03)
==========================

Substantive iteration: the project author supplied the
three OpenSCAD libraries directly, closing the
description-only gap that 0.8.1 acknowledged honestly.
The Modelling Approach Audit extends with empirical
confirmations from direct source reading. Separately, the
Wikipedia coverage map landed, completing the smallest of
the three planned audits.

* Empirical confirmations from direct source reading

  Two new subsections in Concept.org § Modelling Approach
  for the BSPP Model Library:

  - Empirical confirmations from direct source reading
    (0.8.3): Records what was read in 0.8.3 (Makrokaba
    full source, doommeister fitting scripts full source,
    doommeister round-ducting library full source) and
    what survives, what extends, and what is now
    explicitly minority-pattern in the 0.8.1 architectural
    decisions.

  - Patterns from doommeister round-ducting library:
    Three-layer composition (end + middle + end with
    composable middles); parametric port-count for
    manifolds and N-way tees (manifold_n(ways=3, ...)).
    Both worth borrowing for BSPPFit.

  Key findings:

    Compositional pattern fully confirmed: Makrokaba
    ships six adapter files (External-External,
    External-Nozzle, Internal-External,
    Internal-Internal, Internal-Nozzle, Nozzle-Nozzle)
    explicitly enumerating the end-pair Cartesian
    product reduced to 6 by symmetry. Independent
    threads per end mean Makrokaba is a universal-
    adapter library, broader than BSPPFit's BSPP-centred
    scope.

    Self-correcting middle-diameter: Makrokaba's
    create_middle silently raises mid_outer_diameter to
    the larger thread support diameter when the user
    requests something geometrically impossible. New
    pattern to borrow.

    Gender handling minority-pattern acknowledged: the
    0.8.1 single-module-with-parameter choice follows
    doommeister's fitting_end (male=true|false), but
    Makrokaba and uwo-fast use two parallel modules.
    Empirical count is two-out-of-three two-module vs
    one single-module. BSPPFit's choice stands but is
    documented as minority pattern.

    Two-layer module convention: doommeister names
    wrapper as pipe(size=0.5, ...) and implementation
    as _pipe(core, od, tpi, pod, pt, ...). Adopt the
    underscore convention for BSPPFit.

    Test-area / library-mode duality: doommeister's
    explicit "// Test Area - uncomment to draw" comment
    markers plus a small toggleable demo block.
    Visually clearer than uwo-fast's export = false
    flag. Adopt for BSPPFit.

    Threadlib API surface confirmed: thread_specs(designator)
    returns [P, Rrot, Dsupport, profile]. Useful baseline
    if BSPPFit ever switches threading layers.

    Standards reference broadening: doommeister cites BS
    1387 (steel pipe dimensions) and BS 21 (BSP threads,
    pre-ISO ancestor of BSPT).

  Two of the 0.8.1 architectural decisions extended:

    Standard-size handling extends from "designator-keyed
    primary" to also adopting threadlib's CSV-source-of-
    truth + script-generated-OpenSCAD pattern.
    Models/Util/dimensions.csv becomes the canonical
    source.

    Documentation generation extends from "gallery
    modules" to also adopting doommeister's "test area"
    comment-toggle convention.

  Honest limit retired: the depth-of-reading imbalance
  acknowledged in 0.8.1 is closed; reading is now full
  for all three libraries. New limit takes its place: the
  threadlib bundled in Makrokaba's libraries.zip is one
  specific version (V0.3, 2020-05-25); upstream may have
  evolved.

  Provenance chain fully traced: Kirshner -> doommeister
  (modified); Schlatter -> Makrokaba (uses) -> uwo-fast
  (uses Schlatter, inspired by Makrokaba).

* Wikipedia coverage map

  New top-level section "Coverage map vs Wikipedia
  /Piping and plumbing fitting/" in Taxonomy.org. Section
  anchor: wikipedia-coverage-map. Three sub-matrices
  plus a borrow-candidates list:

  - 17-row matrix mapping Wikipedia subject-categories
    (joinery / direction-change / branching / reducing /
    linear-extension / closures / materials / adjacent
    fitting families) against BSPPFit's facet/section
    coverage, classified as match / partial / Wikipedia-
    only / BSPPFit-narrower.

  - What BSPPFit covers that Wikipedia does not:
    BSPP-specific designation analysis, per-size dimension
    tables, selection scenarios SC-01..SC-09,
    sealing-mechanism comparison in F-05, French-trade
    vocabulary via the bilingual section, and the
    parametric model library traceable to the taxonomy.

  - What Wikipedia covers that BSPPFit intentionally does
    not: plastic fittings, DWV drainage, pigging-specific
    fittings, compression and flare as primary subjects,
    slip and rotary unions.

  - Borrow-from-Wikipedia candidates list: 22.5° elbow,
    long-radius vs short-radius elbow, street elbow,
    plumbing-vs-protractor angle clarification, wye as
    separate F-01 entry from tee, close nipple as
    length-of-thread sub-variant. Tracked as a separate
    TODO in FutureResearch for adoption-decision.

* FutureResearch updates

  - Wikipedia coverage map TODO: closed (DONE) with
    summary of output and currency note (point-in-time
    review; Wikipedia article evolves).

  - New TODO "Borrow-from-Wikipedia candidates from
    coverage map": 0.25-day effort to decide each
    candidate adopt vs reject with rationale.

* Phase 1 completion status (iteration 0.8.3)

  Per-component:
    Descriptive taxonomy        ~96% (up from ~95%; the
                                 Wikipedia coverage map
                                 adds positioning
                                 documentation)
    Illustrations                ~50% (no change)
    Per-size dimension tables   100% (unchanged)
    Validation pass             100% (unchanged)
    BSPP 3D model library         7% (up from ~5%; the
                                 architecture is now
                                 verified against direct
                                 source rather than
                                 inferred)

  Weighted Phase 1 aggregate: roughly 60.5% (up from ~60%).


Version 0.8.2 (2026-05-03)
==========================

Substantive iteration: the French glossary lands as a new
"Bilingual Labels --- English <-> French" section in
Taxonomy.org. Eight sub-sections of bilingual tables, plus a
Practical sizing note documenting the French 15x21-family
designations, plus an explicit out-of-scope block. The next
round of project-author photography (slots I-03, I-07, I-08
and any future French-labelled fitting on the workbench) is
unblocked: identification path is read the French
designation off the fitting -> look up the bilingual table ->
find the English class.

* Bilingual Labels section in Taxonomy.org

  - New top-level section "Bilingual Labels --- English
    <-> French" inserted between the Glossary and Sources
    and Attributions. Section anchor: bilingual-glossary.

  - Nine bilingual tables, one per glossary sub-section,
    plus the Practical sizing note table:
      Thread forms                  (BSPP, BSPT, NPT,
                                     Whitworth, Sellers,
                                     pas du gaz)
      Geometry and ports            (banjo bolt, bore,
                                     bushing, cap,
                                     coupling, cross,
                                     elbow, fitting, hex
                                     bush, hose tail,
                                     inlet, manifold,
                                     nipple, outlet, plug,
                                     port, reducer,
                                     socket, tee, union)
      Gender                        (female, male, mixed)
      Sealing                       (anaerobic sealant,
                                     bonded washer,
                                     compression set,
                                     cone seat, gasket,
                                     O-ring, PTFE tape,
                                     sealant generic,
                                     filasse + paste)
      Materials                     (brass, CW614N/CW617N,
                                     dezincification,
                                     dielectric union,
                                     DZR, galvanic
                                     corrosion, galvanised
                                     steel, stainless)
      Pressure ratings              (burst, high, low,
                                     moderate, PN16-40,
                                     pipe class, derating,
                                     schedule, working
                                     pressure)
      Approvals                     (3.1, ACS, KTW, WRAS)
      Tools and trade terms         (faucet, hose clamp,
                                     Jubilee clip,
                                     plumber's leak
                                     argot, shutoff tap/
                                     valve, spigot,
                                     stopcock, tap,
                                     worm-drive clamp)
      Application terms             (compression fitting,
                                     push-fit, PTFE,
                                     sweat fitting,
                                     solvent-weld)

  - Practical sizing note: documents the French
    15x21-family designations (8x13 -> G1/4, 12x17 -> G3/8,
    15x21 -> G1/2, 20x27 -> G3/4, 26x34 -> G1, 33x42 ->
    G1 1/4, 40x49 -> G1 1/2, 50x60 -> G2). This is the
    designation form that appears on metropolitan-France
    domestic-plumbing fittings, often without the BSPP
    designator on the packaging.

  - What this section does not cover block enumerates
    explicit out-of-scope vocabulary: pipe materials
    beyond brass and steel, hydraulic/pneumatic specialised
    vocabulary beyond BSPP intersection, sanitary fittings
    DIN 11581.

  - Items where the assistant had material doubt are
    flagged [a verifier] inline; the project author is
    invited to correct them as journal entries in
    subsequent iterations.

* Sources used for the bilingual section

  - AFNOR vocabulary: NF EN ISO 228-1 (BSPP), NF EN
    10226-1 (BSPT), NF E 03-005 (historical, replaced by
    ISO but vocabulary persists in trade usage).

  - Wikipedia FR articles: Filetage gaz, Collier de
    serrage, Joint torique, Raccord de tuyauterie.
    License CC BY-SA 4.0; usage is paraphrased, no
    article text is reproduced.

  - Office Quebecois de la Langue Francaise / Grand
    dictionnaire terminologique: confirmed for raccord
    cannele <-> raccord a barbillon <-> hose barb mapping.

  - Manufacturer catalogues in metropolitan France: Comap,
    Watts, Wurth FR, Raccordspro, Axesspack, h7g6.fr,
    multicuves.com (for living trade vocabulary,
    particularly the genericised brand-names like
    Serflex, Joint Dowty, Joint Usit, Telon).

* FutureResearch French glossary TODO closed

  - The TODO opened in iteration 0.8.0 moves from TODO
    to DONE. Closure note records the format choice (one
    bilingual table per sub-section, sorted by English
    term, rejected inline-parenthetical and
    inline-plus-table alternatives), the sources used,
    the honest limits surfaced, and the project-value
    link (next round of project-author photography is
    unblocked).

* Phase 1 completion status (iteration 0.8.2)

  Per-component:
    Descriptive taxonomy        ~95% (up from ~92%; the
                                 bilingual section enriches
                                 the taxonomy by adding
                                 French vocabulary across
                                 all eight sub-sections
                                 and by documenting the
                                 French sizing conventions
                                 that appear on
                                 metropolitan-France
                                 fittings)
    Illustrations                ~50% (no change)
    Per-size dimension tables   100% (unchanged)
    Validation pass             100% (unchanged)
    BSPP 3D model library         5% (no change;
                                 architecture recorded,
                                 no code yet)

  Weighted Phase 1 aggregate: roughly 60% (up from ~59%).


Version 0.8.1 (2026-05-03)
==========================

Substantive iteration: the Modelling Approach Audit closes
with a synthesised "Modelling Approach for the BSPP Model
Library" section landing in Concept.org. No model code yet ---
the architecture lands first, by design --- but the
architectural decisions are now recorded with their
alternatives and trade-offs. The iteration also ratifies a
splitting policy that defaults to combining substantive work
into single iterations rather than shipping in small clean
batches, in response to the project author's token-window
constraints.

* Modelling Approach for the BSPP Model Library (Concept.org)

  - New 350-line section in Concept.org. Inserted between the
    Related Work section and Completion Status. Eight
    architectural-decision subsections, one "What remains
    open" subsection, one currency stamp.

  - Each decision presents: alternatives observed in the
    surveyed libraries, trade-offs, choice for BSPPFit. The
    section is "a record of decisions made at the
    architectural moment", not a contract frozen for ever.

  Decisions made:

    Threading layer:
      BOSL2 (consistent with our existing dependency stack;
      bspp_threaded_rod and npt_threaded_rod ready-made;
      single $slop tolerance acceptable when layered with
      asymmetric named tolerances on top).

    Parameterisation of nominal size:
      Designator-keyed primary (G1/2, R1/2, 1/2-NPT), with
      a raw-OD/pitch fallback for non-standard cases. BSPP
      is defined by the standard sizes; the API enforces
      "use the right size".

    Gender handling:
      Single module per fitting with a "gender" parameter
      taking "male"/"female" or BSPT's "R"/"Rc"/"Rp". Not
      the two-module pattern from uwo-fast --- the
      parallelism is one fitting in the taxonomy, not two.

    Composition:
      Facet-keyed record using F-01..F-08 as the schema.
      A fitting is described by the values of its eight
      facets; the user-facing API is named arguments
      with sensible taxonomy-derived defaults. /This is
      BSPPFit's distinctive contribution to the
      modelling-pattern landscape./

    File and namespace organisation:
      Folder per geometry class matching F-01's G-01..G-09
      enumeration. Models/Geometry/Straight.scad,
      Models/Geometry/Elbow.scad, etc.

    Tolerance handling:
      Multiple named parameters --- tol_thread, tol_gasket,
      tol_face, tol_pipe --- not a single global $slop.
      Different fits in the same fitting have different
      tolerance budgets.

    Documentation generation:
      Each parametric file ships a gallery module that lays
      out variants. The gallery and the user-callable module
      share code, so the gallery cannot drift from the
      implementation. Galleries are what make pdf will render
      into figure form.

    Provenance and credit:
      BOSL2 (BelfrySCAD, BSD-2) as threading dependency.
      uwo-fast/pipe-fitting-SCAD + Brooks et al. 2025 paper
      for published patterns. Makrokaba for the
      compositional principle. Doommeister for the geometric
      vocabulary. Threadlib (Adrian Schlatter) referenced as
      the alternative threading layer considered.

* Modelling Approach Audit closed (FutureResearch.org)

  - The audit, opened in 0.7.2 and started in 0.8.0, moves
    from STARTED to DONE. Closure note records the
    coverage achieved (full source reading of two
    uwo-fast files; description-level reading of
    doommeister and Makrokaba, blocked by 403 from
    Thingiverse; full read of the open-access MDPI
    paper) and the honest limits (depth of reading was
    uneven; synthesis is biased toward uwo-fast's
    vocabulary).

* Splitting policy: default to combined substantive iterations

  - Recorded in the journal as a project-author decision.
    Future iterations bias toward combining substantive
    work into single deliveries rather than shipping in
    small clean batches. The propose-not-produce rule from
    the Development Standard is unaffected; only the
    default answer to "should this be split or continued"
    changes.

* Phase 1 completion status (iteration 0.8.1)

  Per-component:
    Descriptive taxonomy        ~92% (no change)
    Illustrations                ~50% (no change)
    Per-size dimension tables   100% (unchanged)
    Validation pass             100% (unchanged)
    BSPP 3D model library         5% (up from 0%; the
                                 architecture is recorded
                                 with alternatives
                                 considered, before any
                                 code is written --- the
                                 leverage point intent of
                                 the audit)

  Weighted Phase 1 aggregate: roughly 59% (up from ~57%).


Version 0.8.0 (2026-05-03)
==========================

Substantive iteration: four illustrations land with full
attribution, the build system is fixed against autoconf's
configure~ backup files surviving make maintainer-clean, the
auto-generated documentation sitemap is replaced with an
authored Index.org modeled on the project author's svah
project, and the Modelling Approach Audit is started (one of
three target libraries read; synthesis split off to 0.8.1).

* Four illustrations placed with attribution

  - I-01 WhitworthThread.svg (CC BY-SA 4.0; Original: Tjt263,
    Vector: AntiCompositeNumber, via Wikimedia Commons).
    Embedded at the F-03 Comparison subsection of the
    Taxonomy as the canonical 55° Whitworth profile diagram.

  - I-02 BondedWasher.png (Public domain; Wikipedia user
    Brotherpete, created with Paint.net, via Wikimedia
    Commons). Embedded under the bonded-washer entry in F-05
    of the Taxonomy. The diagram shows outer hard ring and
    inner soft ring with labelled callouts.

  - I-04 BSPPMaleStraightThread.png (CC BY-SA 4.0; Kees08,
    via Wikimedia Commons). The original 65.5 MB file was
    downsampled by the project author to a project-archive-
    reasonable 19 KB. Embedded in the BSPP subsection of
    F-03.

  - I-05 WormDriveHoseClamp.png (Project author's own
    photograph, GPL v3+). Three hose-clamping mechanisms
    side by side. Embedded in the glossary at the
    "Worm-drive clamp" entry.

  A new "Sources and Attributions" section in Taxonomy.org
  consolidates the per-illustration credit in a six-column
  table (Slot / File / Title / Author / License / Source).
  CC BY-SA 4.0 illustrations are reproduced under the
  Creative Commons one-way GPL-v3 compatibility recognised
  since 2015; the aggregate is licensable consistently.

  Catalogue updates:
    I-03 cone seat: RESTARTED (project author rejected the
                    Wikipedia JIC-fitting source as
                    conflating mechanisms; alternative
                    search tracked in FutureResearch).
    I-06 pipe-fitting types overview: DISMISSED (out of
                    scope; mixes non-BSPP fitting families).
    I-07 O-ring: DEFERRED (project author plans own
                    photographs).
    I-08 BSPT taper geometry: DEFERRED (project author plans
                    to provide).

* Build fix: configure~ backup file cleaning

  - Top-level Makefile.am MAINTAINERCLEANFILES gains
    configure~, aclocal.m4~, Makefile.in~. These are NOT
    Emacs backup files (the project author confirmed not
    using make-backup-files); they are autoreconf's safety
    backups produced when it regenerates an existing file.
    Without listing them they survived make maintainer-
    clean and accumulated.

  - Doc/Makefile.am MAINTAINERCLEANFILES gains Makefile.in~
    for the same reason.

  - Doc/Makefile.am CLEANFILES no longer contains a
    blanket *.png pattern. PNGs under Doc/Illustrations/
    are project sources (project-author photographs and
    license-clean external images) that make clean must
    not delete. A code comment explains the rationale.

* Authored Index.org replaces auto-generated sitemap

  - Doc/Index.org: new top-level documentation index modeled
    on the project author's svah Index.org. Versioned
    subtitle via #+INCLUDE: version.org. An Introduction
    section setting project context. Grouped sections
    (Project constitution and standards / Concept and scope
    / Reference content / Research and planning / Asset
    catalogues) with each link annotated by a one-sentence
    description.

  - Doc/batch-init.el: org-publish-project-alist drops
    :auto-sitemap and the post-publish sitemap.html ->
    index.html rename. Index.html is now built normally as
    one of the project's HTML documents.

  - Doc/Makefile.am: Index.org added to DOC_FILES; the old
    "html.stamp index.html sitemap.org" CLEANFILES line is
    reduced to "html.stamp" since Index.html is now cleaned
    via $(HTML_DOCS).

* Modelling Approach Audit started (split off to 0.8.1)

  - Read uwo-fast/pipe-fitting-SCAD's pfDesigner.scad via
    web_fetch on the GitHub file-view page (raw URL was
    blocked, consistent with the cache-only-domain pattern).

  - Findings recorded in FutureResearch.org under "Notes
    from 0.8.0 in-flight reading": parameterisation strategy
    (hybrid raw-input + thread-table search returning a list
    of valid designators), explicit Upper/Middle/Lower
    composition, multi-design preview pattern, asymmetric
    tolerance handling (tol_pipe + tol_gasket vs BOSL2's
    single $slop), $preview/$fn rendering switch, the fudge
    factor for circle subtraction.

  - Audit entry's TODO state changes to STARTED. Doommeister,
    Makrokaba, and the synthesis remain for 0.8.1.

* Three new TODOs in FutureResearch.org

  - "French glossary --- bilingual labels for fitting
    terms": direct producer of project value because the
    project author's stock of fittings is labelled in
    French; without French equivalents the next round of
    project-author photography cannot proceed.

  - "I-03 alternative cone-seat illustration source":
    search angles include Wikimedia Commons subcategories,
    project-author photograph (gated on the French
    glossary), and OpenSCAD render once the model library
    exists.

  - "I-08 BSPT taper geometry diagram": search /
    project-author drawing / OpenSCAD render once the
    library exists.

* Honest disclosure in the journal

  - A journal entry "Honest answer: assistant prioritisation
    bias" records the assistant's confirmation that its
    proposed Modelling-first ordering is partly biased by
    its own confidence in software-architecture work over
    taxonomy-design work. The project author should treat
    future ordering proposals from the assistant with this
    bias in mind. The disclosure belongs in the journal
    rather than the Development Standard because it is a
    diagnosis of one episode rather than a project-wide
    rule.

* Phase 1 completion status (iteration 0.8.0)

  Per-component:
    Descriptive taxonomy        ~92% (no coverage change;
                                 figures now embedded)
    Illustrations                ~50% (up from ~5%; four
                                 of eight slots DONE)
    Per-size dimension tables   100% (unchanged)
    Validation pass             100% (unchanged)
    BSPP 3D model library         0% (Modelling Approach
                                 Audit STARTED, lands
                                 before code does)

  Weighted Phase 1 aggregate: roughly 57% (up from ~52%).


Version 0.7.2 (2026-05-03)
==========================

Minor iteration: documentary reframing and audit planning, no
Phase 1 deliverable state changes. The Related Work section in
Concept.org is reframed --- learning from precedent is now the
primary frame, distinguishing-from is secondary. Three concrete
audit TODOs are opened in FutureResearch.org for execution in
subsequent iterations.

* Related Work section reframed (Concept)

  - Section title changed from "Related Work and
    Differentiation" to "Related Work --- Learning From,
    and Distinguishing From".

  - Lead paragraph now states explicitly that the primary
    purpose of surveying related work is to inherit
    discipline, vocabulary, and modelling decisions from
    earlier efforts; the secondary purpose is to clarify
    what BSPPFit adds. Putting differentiation first read
    as defensive and inverted the operationally useful
    conclusions.

  - Each of the three subsections (BIM, OpenSCAD libraries,
    encyclopaedic sources) now follows the structure:
    items, then "What we can learn", then "What
    distinguishes us". The "What we can learn" blocks
    contain the operationally useful conclusions:
      - From BIM: faceted-classification discipline, ISO
        12006-2 as meta-framework, hierarchical coding,
        Activities and Tools as separate facets.
      - From OpenSCAD libraries: parameterisation of
        nominal size, male/female pair handling,
        file/namespace organisation (e.g., uwo-fast's
        pfDesigner.json metadata schema), composition
        (e.g., Makrokaba's any-combination-of approach),
        documentation generation, tolerance handling.
      - From encyclopaedic sources: Wikipedia's coverage
        map as a benchmark, Machining Doctor's
        redistribution pattern (paraphrase, attribute,
        derive from first principles), Wikipedia
        vocabulary as default for general piping terms.

  - The "Reuse, not reinvent" list is expanded with two
    new entries: faceted-classification discipline (ISO
    12006-2 + UniClass 2015) and modelling architecture
    for the model library.

* Three concrete audits planned (FutureResearch)

  - "Facet audit against ISO 12006-2 and UniClass 2015"
    (1 day): read the standard, map F-01..F-08 against
    UniClass's eleven tables, decide whether to add
    facets, merge facets, or adopt hierarchical coding.

  - "Modelling Approach Audit (read source of three
    OpenSCAD libraries)" (1 day): read the source files
    of uwo-fast/pipe-fitting-SCAD, doommeister, Makrokaba.
    Extract architectural decisions before the BSPP model
    library starts. Highest-leverage of the three audits
    because it informs the largest remaining Phase 1
    component (model library, 35% of Phase 1 effort,
    currently 0% done).

  - "Wikipedia coverage map" (0.5 day): map our Taxonomy
    sections against the Piping and plumbing fitting
    Wikipedia article, identify what each side covers
    exclusively, record explicit borrowings.

  These audits land in subsequent iterations, not this
  one. Executing them now would produce shallow versions;
  the value is in doing them properly.

* Phase 1 completion status (iteration 0.7.2)

  Per-component (unchanged from 0.7.0 and 0.7.1):
    Descriptive taxonomy        ~92%
    Illustrations                ~5%
    Per-size dimension tables   100%
    Validation pass             100%
    BSPP 3D model library         0%

  Weighted Phase 1 aggregate: roughly 52% (unchanged).


Version 0.7.1 (2026-05-03)
==========================

Minor iteration: documentary additions, no Phase 1 deliverable
state changes. Two pieces of project documentation land in this
release: a "Working with the LLM assistant" section in the
Development Standard, and a "Related Work and Differentiation"
section in the Concept. A recurring TODO is opened to re-review
the related-work survey annually.

* Working with the LLM assistant (Development Standard)

  - New top-level section in DevelopmentStandard.org. Records
    what the assistant can and cannot do in this project's
    working environment, so that work is divided correctly
    and so that the v0.6.0 hand-drawn-SVG mistake is not
    repeated.

  - Subsections cover: visual perception (and its absence
    in this deployment), implication for illustration work,
    web access (and the cache-only-domain constraint),
    implication for research and gathering work, drawing
    tools and their limits, what the assistant should
    propose rather than produce, and self-knowledge limits.

  - The "what the assistant should propose, not produce"
    rule is the formal codification of the v0.6.0-prevention
    workflow: when a piece of work falls outside the
    assistant's environment's capabilities, the assistant
    proposes the work with a specification rather than
    producing a degraded version.

* Related Work and Differentiation (Concept)

  - New section in Concept.org. Surveys three families of
    adjacent work: BIM industry classification standards
    (OmniClass, UniClass 2015, MasterFormat, UniFormat,
    SfB family), open-source OpenSCAD model libraries
    (BOSL2, NPT_Library, pipe-fitting-SCAD, threadlib,
    DimensionPrint, Makrokaba, doommeister), and
    encyclopaedic / educational sources (Wikipedia,
    manufacturer guides, ISO/BS standards, trade
    publications).

  - Differentiation conclusion: BSPPFit combines a faceted
    descriptive taxonomy (BIM-spirit at non-specialist
    explanatory depth), validation scenarios as selection
    reasoning, and a parametric model library traceable to
    the taxonomy. No surveyed project combines all three.

  - Reuse / originate split made explicit: BSPPFit reuses
    BOSL2 (threading), paraphrases Machining Doctor's
    published thread-form formulas, and produces
    originally the faceted taxonomy, the validation
    scenarios, and the classified model library.

  - Section is currency-stamped (2026-05-03). The
    OpenSCAD ecosystem evolves rapidly; the section
    advises re-review at the annual cadence.

* Recurring annual research commitment

  - FutureResearch.org gains "Re-review related-work survey
    (recurring)", an entry that never closes. Each annual
    review is logged as a fresh ResearchJournal entry under
    the pattern "Related work survey".

* Phase 1 completion status (iteration 0.7.1)

  Per-component (unchanged from 0.7.0):
    Descriptive taxonomy        ~92%
    Illustrations                ~5%
    Per-size dimension tables   100%
    Validation pass             100%
    BSPP 3D model library         0%

  Weighted Phase 1 aggregate: roughly 52% (unchanged).

  This iteration does not move Phase 1 progress; the
  contribution is documentation hygiene that supports
  future iterations.


Version 0.7.0 (2026-05-02)
==========================

Iteration addressing the v0.6.0 review: the v0.6.0 hand-drawn
SVGs are retracted (they were a hodge-podge); illustration
strategy switches to license-clean external sources catalogued
for the project author to fetch and credit; directory naming
brought into line with the convention; PDF version macro fixed
so the title page shows the full v0.7.0 string instead of just
the SVN revision; glossary intra-references converted from
italic text to actual anchored links.

* Illustrations: retraction of v0.6.0 SVGs; new sourcing strategy

  - The three SVG files committed in v0.6.0 (dowty-seal.svg,
    cone-seat.svg, thread-profiles.svg) have been deleted.
    The project author judged the first two as a hodge-podge
    and was correctly skeptical that the assistant could draw
    correct mechanical cross-sections without seeing the
    parts.

  - New strategy: web-sourced illustrations with priority on
    compatible licensing (CC0, CC BY 4.0, CC BY-SA 4.0). Where
    no compatible licence is available, the project credits
    the source, acknowledging that the project licence becomes
    tainted in a strictly-aggregate sense until project-author
    photographs and model-library renders replace the
    externally-sourced files.

  - The closed-loop plan (project-author framing): external
    illustrations as references --> project-author photographs
    using the illustrations as framing/orientation guides -->
    eventually OpenSCAD/BOSL2 renders replacing both. At each
    step the externally-credited material drops out.

  - Doc/Illustrations/Catalogue.org: new working catalogue
    listing 8 candidate slots (I-01..I-08), each with source
    URL, license, attribution string template, role in the
    project, and target local PascalCase filename. Slots
    cover: Whitworth thread profile, bonded seal washer,
    cone seat / JIC, BSPP male thread photograph, worm-drive
    clamp, pipe fitting types overview, O-ring cross-section,
    BSPT taper geometry.

  - The Wikimedia Commons file Whitworth_Thread.svg
    (CC BY-SA 4.0, 1703x992 px, ~63 KB) is identified as the
    primary candidate for the thread-profile slot. The
    Wikimedia file BSPP Male Straight Thread.png is
    identified for the BSPP-photograph slot (with a note that
    the 65 MB raw should be downsampled before placement).

  - Body text in Taxonomy.org retains the previous figure
    positions; each former embedding is replaced with a
    one-paragraph forwarding note pointing to its catalogue
    slot. When the project author fetches a file and updates
    the catalogue's status, the forwarding note is replaced
    with the actual embedding directive.

  - FutureResearch entry "Thread cross-section illustrations
    (first set)" reopened as RESTARTED (was DONE in v0.6.0)
    with explicit retraction note and new closure criteria.

* Directory naming: illustrations/ -> Illustrations/

  - The v0.6.0 lowercase illustrations/ violated the project's
    PascalCase file-naming convention. Renamed to
    Illustrations/ in v0.7.0.

  - Development Standard /Naming Convention Scope/ subsection
    enhanced with a Common lapse note: subdirectories created
    mid-project for new artefact classes (Illustrations/,
    Models/, Captures/, Schemas/) are subject to the same
    rule. The shell-friendliness of an all-lowercase name is
    not a justification.

* PDF version macro: REVISION uniformed across backends

  - v0.6.0 PDFs displayed only the SVN revision number on the
    title page, not the full v0.6.0.NNN string. Cause: the
    macro REVISION expanded to v\svnInfoRevision for LaTeX,
    but each document's #+LATEX_HEADER: \svnInfo $Id$ ran
    after the include and redefined \svnInfo, overwriting the
    title-page revision.

  - Fix: Doc/version.org.in now defines REVISION as
    v@PACKAGE_VERSION@ for both backends. The
    \svnInfoRevision indirection is removed; configure.ac
    already substitutes the full version string from the
    VERSION file.

  - The per-file \svnInfo $Id$ directives still work for
    page-footer revisions; only the title-page macro path is
    changed.

* Glossary intra-references: anchor-and-link mechanism

  - v0.6.0 glossary used /See /Term/./ inside description-list
    bodies to cross-reference between entries. This is italic
    text, not a link, in both PDF and HTML output --- so a
    reader who saw "See Shutoff tap" had no clickable path.

  - v0.7.0 fix: each canonical glossary entry gains an inline
    anchor <<term-canonical-name>> immediately after the ::
    separator. Synonym entries and intra-glossary references
    use [[term-canonical-name][display]] links instead of
    italic text. Affected entries: term-inlet, term-outlet,
    term-manifold, term-nipple, term-tap, term-faucet,
    term-spigot, term-shutoff-tap, term-shutoff-valve,
    term-stopcock, term-worm-drive-clamp, term-jubilee-clip,
    term-hose-clamp, term-hose-clip, term-leak-argot.

  - Body uses also re-pointed:
      SC-01 worm-drive clamp -> term-worm-drive-clamp
      SC-03 shutoff tap      -> term-shutoff-tap
      F-08 Pneumatic manifold -> term-manifold

  - Glossary Coverage Rule (Development Standard) gains the
    requirement that entries be linkable, not just present.

* Phase 1 completion status (iteration 0.7.0)

  Per-component:
    Descriptive taxonomy        ~92% (no change in coverage;
                                 intra-links now functional)
    Illustrations                ~5% (down from 25%; v0.6.0
                                 SVGs retracted, catalogue
                                 added)
    Per-size dimension tables   100% (unchanged)
    Validation pass             100% (unchanged)
    BSPP 3D model library         0% (unchanged)

  Weighted Phase 1 aggregate: roughly 52% (down from 54%,
  reflecting the illustrations retraction).


Version 0.6.0 (2026-04-30)
==========================

Iteration addressing the v0.5.0 review: HTML cross-document
warnings actually fixed (the v0.5.0 fix didn't work and is
retracted), per-size dimension tables for BSPP / BSPT / NPT
added, first illustration set committed (SVG cross-sections
of bonded seal washer, cone seat, and thread profile
comparison), Glossary Coverage Rule for trade and dialect
terms, Phase 1 completion status moved out of the Concept
back into the ResearchJournal where it belongs, validation
pass closed.

* HTML cross-document anchor resolution

  - The v0.5.0 attempt at fixing the "Reference X in file Y
    cannot be resolved without publishing" warnings did not
    work. Defining org-publish-project-alist alone is not
    sufficient: the resolver only succeeds when called from
    inside an actual org-publish-* run. v0.5.0 set up the
    project but never entered it; the warnings persisted and
    the rendered HTML carried real broken-link markers.

  - v0.6.0 fix: HTML build now uses org-publish-all (entry
    point bsppfit/publish-all in Doc/batch-init.el) instead
    of per-file org-html-export-to-html. The resolver
    succeeds because the project run is genuinely in
    progress.

  - Side benefits of switching to org-publish-all:
    - Auto-generated index.html landing page, listing every
      document in the project as a navigable bundle.
    - HTML export is now one Emacs invocation per build
      instead of six.
    - Genuine broken links are reported as broken-link
      markers; the noise floor is zero.

  - Doc/Makefile.am: %.html: %.org pattern rule replaced
    with a single html.stamp: $(DOC_FILES) stamp-driven
    rule. CLEANFILES extended with html.stamp, index.html,
    sitemap.org.

* Per-size dimension tables

  - New top-level section "Per-size dimension reference
    (BSPP, BSPT, NPT)" in Taxonomy.org with three captioned
    tables:
      tab:bspp-dimensions  G1/16 .. G3, ISO 228-1
      tab:bspt-dimensions  R1/16 .. R2 at gauge plane, ISO 7-1
      tab:npt-dimensions   1/16 NPT .. 2 NPT, ANSI/ASME B1.20.1
    Each row carries TPI, pitch (mm), OD, useful thread
    length. A "How to read the tables" subsection guides
    the reader; a "Sources and verification" subsection
    names the standards.

  - The BSPT table mirrors the BSPP table at the same
    nominal sizes: same TPI, same OD per row, only the
    parallel-vs-tapered column differs --- which makes the
    BSPP × BSPT confusion (SC-04) visible at the
    table-row level.

* Illustrations

  - First three SVG cross-section illustrations committed
    under Doc/illustrations/, embedded in Taxonomy.org with
    captions and figure-list registration:
      thread-profiles.svg  55 deg Whitworth vs 60 deg
                           American profile comparison,
                           next to tab:thread-forms
      dowty-seal.svg       bonded seal washer compressed
                           cross-section, in F-05 sealing
      cone-seat.svg        60 deg hydraulic cone-seat
                           metal-to-metal seal, in F-05
                           sealing

  - Tooling decision: hand-written SVG rather than the
    originally-planned TikZ. Portable across HTML and LaTeX
    without conversion, editable as readable XML in any
    text editor, and visible in any browser tab. TikZ
    remains available for parametric or
    scientific-publication illustrations; Graphviz remains
    the right tool for relationship diagrams.

  - Taxonomy.org now declares \listoffigures{} since it
    carries figures.

* Glossary

  - Glossary Coverage Rule (Development Standard, new
    subsection): every domain term used in a body must have
    a glossary entry. Trade and dialect terms count;
    regional synonyms get cross-referenced entries pointing
    to a canonical form.

  - New entries in the Taxonomy glossary under a new "Tools,
    accessories, and trade terms" subsection:
      Worm-drive clamp (canonical) + synonyms Jubilee clip,
        hose clamp, hose clip
      Shutoff tap (canonical) + synonyms shutoff valve,
        stopcock
      Faucet, spigot, tap (with British vs North American
        sense distinction)
      Plumber's argot --- "leak" (seep / weep / leak
        distinction)

* Concept and ResearchJournal

  - Completion Status accounting moved out of Concept.org
    back into ResearchJournal.org, where it belongs. The
    v0.5.0 placement was the result of bad reasoning that
    inverted the reverse-chronology argument; the project
    author flagged this during review and the decision is
    retracted in a dedicated journal entry.

  - Concept.org now carries a five-line forwarding
    paragraph titled Completion Status that points the
    reader at the journal entry. The forwarding paragraph
    is static; it does not move from iteration to
    iteration.

  - Development Standard Completion Status Rule rewritten
    to specify journal placement and explain why (concept
    is for what completion is, journal is for where the
    project stands).

* Phase 1 completion status (iteration 0.6.0)

  Per-component:
    Descriptive taxonomy        ~92% (was ~85%)
    Illustrations               ~25% (was 0%)
    Per-size dimension tables   100% (was ~10%)
    Validation pass             100% (was 0%)
    BSPP 3D model library         0% (unchanged)

  Weighted Phase 1 aggregate: roughly 54% (was ~35%).

  Two of the five maturity components are now green
  (validation pass, per-size tables). The remaining work
  is dominated by the 3D model library.

* Validation pass

  All nine scenarios (SC-01..SC-09) walked through against
  the populated taxonomy by the project author and found
  feasible / understandable. Two qualitative findings
  recorded for future format work: the link-based "Facets
  exercised" list earns its keep as a learning tool
  independent of validation; the four-section structure
  (Situation / Facets / Expected / Caveats) works in
  practice. The validation pass is closed for Phase 1.


Version 0.5.0 (2026-04-29)
==========================

Iteration addressing the v0.4.0 review: HTML cross-document
warnings resolved at their cause, validation scenarios given
an explicit Expected-resolution section, taxonomy clarified on
BSPT designations / 1:16 taper / inlet-and-outlet / French
sizing notation / gas-and-steam thread form / gasket / pressure
bands, glossary enriched and re-sorted, Concept document gains
an honest Completion Status section.

* HTML cross-document anchor resolution

  - HTML export now defines a minimal org-publish-project-alist
    (in Doc/batch-init.el) so that the anchor resolver can find
    the project's .org files. The "Reference X in file Y cannot
    be resolved without publishing" warnings observed during
    HTML export of v0.4.0 are gone.

  - The fix is no-cost: the project entry exists solely so the
    resolver can find the files; export continues to be
    triggered per-document by org-html-export-to-html.

* Validation scenarios

  - Each scenario now has the same four-section structure:
    Situation, Facets exercised, Expected resolution, and
    (optional) Caveats. The Expected-resolution section is
    new for SC-01..SC-05; SC-06..SC-09 already had reasoning
    sections, which were lifted into the same shape.

  - Without an Expected-resolution section a scenario is a
    description of a problem, not a test of the taxonomy.
    The test for "did the documentation work" is now
    unambiguous for every scenario.

  - Format codified as a Development Standard rule
    (Validation Scenario Format).

* Taxonomy

  - F-03 (Thread form): BSPT R / Rc / Rp designation prefixes
    each get a paragraph; new "1:16 taper, in plain numbers"
    sub-section explains the taper rate concretely.

  - F-02 (Gender): new "What inlet and outlet mean here"
    sub-section, distinguishing flow-direction labelling from
    fixed-end labelling and listing three reasons it matters
    (direction-sensitive devices, gendered fittings, tool
    access).

  - F-04 (Nominal size): new "Bore and thread-OD notation"
    sub-section covering the European 15/21, 20/27, ... form
    with an equivalence table to ISO designations and
    measured values.

  - F-05 (Sealing mechanism): the "Flat-face crush gasket"
    entry was widened into a "Gasket" entry covering soft /
    composite / soft-metal variants, which the Steam
    application context relied on implicitly.

  - F-07 (Pressure rating): new "What low, moderate, and
    high pressure mean here" sub-section with a five-band
    convention table, and an explicit definition that bare
    "high pressure" in the document means 16-40 bar.

  - F-08 (Application context): the Gas and Steam paragraphs
    each gained a thread-form discussion (BSPT-with-tapered-
    threads is the convention; BSPP-with-bonded-washer is a
    secondary case at low pressure or flange interfaces).
    Pneumatic now hyperlinks "manifold" to the new glossary
    entry.

  - Glossary: new entries (Bore, Inlet, Outlet, Manifold,
    Gasket, R-and-Rc-and-Rp, Low/Moderate/High pressure
    bands). All entries re-sorted alphabetically within each
    thematic group; the top-level "Geometry" group renamed to
    "Geometry and ports" to accommodate the port-related
    additions.

* Concept

  - New "Completion Status (as of iteration 0.5.0)" section.
    Honest accounting of how far Phase 1 has travelled, by
    component:
      Descriptive taxonomy:        ~85% done
      Illustrations:                  0% done
      Per-size dimension tables:    ~10% done
      Validation pass:                0% done
      BSPP 3D model library:          0% done
    Weighted Phase-1 aggregate: roughly 35%.

  - The pattern is codified as a Development Standard rule
    (Completion Status Rule). The completion-status section
    is updated every iteration to keep the project's place in
    the journey legible.


Version 0.4.0 (2026-04-27)
==========================

Iteration addressing the v0.3.0 review: build-tool detection
promoted to errors for required tools, multi-pass LaTeX bound
to latexmk where available, default target produces the
documentation, cross-document references upgraded to real
hyperlinks, taxonomy fleshed out across all facets and
extended with four new validation scenarios.

* Build system

  - configure.ac now categorises tools into Required, Recommended,
    and Optional. Missing required tools (Emacs, lualatex, GNU
    make) produce AC_MSG_ERROR; missing recommended tools
    (latexmk) produce AC_MSG_WARN with a documented fallback;
    missing optional tools (PlantUML, Graphviz) produce
    AC_MSG_WARN with no fallback (only the documents that use
    them are affected).

  - configure.ac ends with a summary block listing the resolved
    path of each tool, so the user sees at a glance which
    features will and will not work.

  - "make" with no argument now produces the PDF documents (the
    iteration's deliverable) via "all-local: pdf-local" in
    Doc/Makefile.am. HTML stays opt-in via "make html".

  - The [undefined reference] warning observed in v0.3.0 on
    DevelopmentStandard.org and Taxonomy.org is fixed at its
    cause. PDF export is now a single latexmk invocation that
    iterates to convergence; if latexmk is absent, the build
    falls back to four explicit lualatex passes (one more than
    the Org-mode default of three).

  - The Emacs Lisp setup that was previously inlined in
    Doc/Makefile.am as long --eval chains is now in
    Doc/batch-init.el, loaded via "emacs --load". Configurable
    values (paths to lualatex, latexmk, plantuml.jar, choice of
    PDF process) pass through environment variables, which
    avoids the shell-quoting hazards of nested double-quoted
    elisp.

* Cross-document references

  - New Development Standard rule: every cross-document and
    cross-section reference in prose must be a real Org link,
    not a bare filename. Section "Cross-References Between
    Documents" documents the link forms, the HTML/PDF behaviour,
    and the convention for naming stable <<anchor>> targets.

  - A LaTeX-export filter (bsppfit/org-link-org-to-pdf, in
    Doc/batch-init.el) rewrites .org -> .pdf in href URL targets
    so that cross-document links in the produced PDFs resolve
    to the rendered PDFs rather than to the source .org files.

  - Existing bare-filename references in Concept.org,
    FutureResearch.org, Taxonomy.org, and prior ResearchJournal
    entries upgraded to hyperlinks. Substance preserved; only
    the link form changed.

* Taxonomy

  - F-02 (Gender), F-04 (Nominal size), F-05 (Sealing
    mechanism), F-06 (Material), F-07 (Pressure and temperature
    rating), F-08 (Application context) all fleshed out with
    /values, conventions, constraints, common errors/
    subsections and supporting tables (sealing-vs-thread,
    material-vs-media, fitting markings, application
    constraints).

  - SC-04 cross-reference to ResearchJournal.org (the example
    Peter flagged in section 4.4) is now a proper hyperlink.

  - Four new validation scenarios:
      SC-06  Hot potable water  -> DZR brass selection
      SC-07  Concentric vs eccentric reducer in a horizontal line
      SC-08  10 bar pneumatic branch tee in a workshop
      SC-09  Read a fitting marking (G1/2 PN16 DZR WRAS)

  - Glossary roughly tripled in size, organised into eight
    thematic groups: thread forms / geometry / gender / sealing
    / materials / pressure-and-ratings / approvals / application
    terms. New terms include DZR brass, dezincification, CW617N
    / CW614N, banjo bolt, compression set, dielectric union,
    galvanic corrosion, schedule, pipe class, PN16/25/40, WRAS /
    ACS / KTW, EN 10204 3.1, tri-clamp, anaerobic sealant, cone
    seat, taper ratio, designation prefix, pitch.

* Future Research

  - Two new TODO items: per-nominal-size dimension tables, and
    thread cross-section illustrations as the first concrete
    TikZ target.


Version 0.3.0 (2026-04-26)
==========================

Build system polish, addressing every warning observed during
exercise of the v0.2.0 delivery, plus documentation conventions
that close the cause of those warnings rather than just their
symptoms.

* Archive layout
  - The collaboration delivery archive no longer contains a
    BSPPFit-VERSION/ wrapper directory. Files extract directly
    into the current directory, matching the project author's
    integration workflow. Distribution archives produced by
    "make dist" continue to use the wrapped layout (autotools
    convention).

* Build warnings resolved
  - Doc/Makefile.am: ORG_SOURCES renamed to DOC_FILES. Avoids
    the automake "_SOURCES primary" warning. The Development
    Standard now documents which suffixes carry automake
    meaning and which do not.
  - configure.ac: AM_INIT_AUTOMAKE gains -Wno-portability
    (silences the GNU-Make pattern-rule warning that we own
    intentionally) and dist-xz (replaces the custom dist-xz
    target that clashed with automake's own).
  - PDF export: Doc/Preamble.tex now declares newunicodechar
    mappings for the prose Unicode characters that lualatex's
    default font lacks (->, <=, >=, *, etc.). The "Missing
    character(s)" warnings disappear without changing the main
    font.
  - PDF export: list-of-figures and list-of-tables directives
    are included only in documents that have captioned
    content. Documents with neither no longer emit the
    "[undefined reference]" warning.
  - HTML export: org-html-htmlize-output-type is set to nil
    by default, which silences the htmlize-version warning.
    Optional upgrade path (install htmlize >= 1.34, set to
    'css for colored source blocks) is documented.
  - maintainer-clean: the autotools-generated files
    (aclocal.m4, configure, Makefile.in, build-aux/*) are now
    listed in MAINTAINERCLEANFILES, with a maintainer-clean-
    local hook removing the build-aux directory and
    autom4te.cache. After "make maintainer-clean", the source
    tree is back to its pre-bootstrap state.

* Shared LaTeX preamble
  - Doc/Preamble.tex is the single source of truth for the
    LaTeX preamble used by every org document: packages,
    hyperref configuration, Unicode mappings. Each document's
    LATEX_HEADER lines shrink to two: one to load the shared
    preamble, one to set the document's own SVN $Id$ keyword.
  - Adding a package or a Unicode mapping is a one-file edit.

* Diagrams and Illustrations
  - The Development Standard now distinguishes "diagrams"
    (structure, behaviour) from "illustrations" (shape,
    content) and prescribes a tool palette beyond PlantUML:
    Graphviz/dot for trees and graphs; TikZ for dimensioned
    drawings and thread cross-sections; OpenSCAD-rendered
    views for model-derived illustrations; Inkscape SVG for
    hand-finished illustrations; photographs for real-world
    reference. A selection cheat-sheet table accompanies the
    section.
  - configure.ac now detects Graphviz dot (warns if absent,
    does not fail).

* Captions for figures and tables
  - The Development Standard now mandates #+CAPTION: and
    #+NAME: anchors on every figure and every table. Existing
    tables in DevelopmentStandard.org and Taxonomy.org have
    been captioned.

* Validation scenarios --- purpose, frequency, scope
  - The role of validation scenarios (SC-01..SC-05) is now
    explicitly documented in ResearchJournal.org. They are
    stress-tests of the taxonomy as a document, applied at
    major milestones, with each scenario exercising at least
    two facets and drawn from a dominant real-world failure
    mode. They are not software unit tests.

* SC-04 revised
  - SC-04 is now a BSPP-vs-BSPT confusion (parallel-vs-tapered,
    same 55-degree Whitworth profile) instead of a BSPP-vs-NPT
    "American hardware store" framing. The new framing is
    accessible to the project author and is also a more
    instructive teaching case (the thread profile is identical,
    making the confusion harder to detect). NPT remains
    documented as an adjacent class but no longer carries a
    validation scenario.

* BOSL2 BSPP module --- dependency pinning resolved
  - The BSPP threading helpers in BOSL2 are confirmed present
    from commit e5b0fcf (January 2026). API is stable.
    Installation procedure (clone + symlink to
    ~/.local/share/OpenSCAD/libraries/BOSL2) is documented in
    DevelopmentStandard.org and in README.


Version 0.2.0 (2026-04-25)
==========================

Build system bootstrap and Phase 1 seeding.

* Autotools scaffolding: configure.ac, Makefile.am at the project
  root and in Doc/, bootstrap script, AUTHORS, ChangeLog,
  README, COPYING (GPL-3), .tar-exclude, NEWS (this file).
* Document export pipeline: Emacs in batch mode produces PDF
  (via lualatex) and HTML from every org document under Doc/.
  PlantUML diagrams are rendered through Org-babel.
* Versioning: four-digit Dewey form (major.minor.sequence.svn)
  driven by the VERSION file with SVN $Revision$ keyword
  expansion. configure.ac assembles the four-digit form for
  document subtitles; the three-digit form is authoritative
  for the archive name.
* Standards merge: the svah project's Development Standard was
  merged into Doc/DevelopmentStandard.org, with BSPPFit-specific
  additions (OpenSCAD with BOSL2 integration patterns)
  preserved.
* Taxonomy seed: Doc/Taxonomy.org introduces the facet
  inventory (F-01..F-08, geometry G-01..G-09), the BSPP/BSPT/
  NPT thread-form comparison, validation scenarios SC-01..
  SC-05, and the glossary.


Version 0.1.0 (2026-04-25)
==========================

Initial bootstrap delivery.

* Concept.org: project goal, motivation, scope. Phase 1
  (BSPP-centred taxonomy with BSPT and NPT as adjacent classes;
  BSPP-only 3D model library) and Phase 2 (deferred extension
  to non-threaded fittings).
* ResearchJournal.org: first decision entry --- project scope.
  Three options considered (pure BSPP, BSPP-centred with
  adjacent classes, thread form as primary axis) with rationale
  for the chosen option.
* FutureResearch.org: Phase 2 entry with explicit re-opening
  trigger.
* ChangeLog: this file.
