Paper Legal — component taxonomy rationale

Why this component exists

Every prior legal-document component in this vault (legal-agency-suite, legal-prospectus, legal-subscription-agreement) is a concrete register: real CSS backing a specific document type, built from a specific source draft. None of them separately captures the drafting convention — heading form, numbering scheme, cross-reference grammar — as a reusable rule set that downstream authors (human or AI) can apply to a new document type without re-deriving it from scratch or copying an existing register that may not actually fit.

paper-legal is the first component built specifically to hold that convention layer. It was requested by project-documents after a blind two-reviewer (Opus + Fable) research pass grounded in filed-exhibit evidence (EDGAR full-text search) and standard drafting-style authorities (Adams/MSCD, Weagree, Canada Justice Legistics, US House Manual on Drafting Style), cross-checked against a real pilot document (the Master Engagement Agreement, JW8/JW9).

Key findings from this session's build

• The 5-category split is evidence-backed, not house style. The commercial-vs-constitutional heading split (flat Section vs. ARTICLE) maps cleanly onto a real, observable pattern in filed agency/underwriting agreements vs. filed shareholder/LP agreements — see the citations list in the recipe and usage.md. This is a genuine reason to keep them as separate variants rather than collapsing to one generic "legal document" heading rule.
• Real naming collision found, not silently resolved. project-documents' own request refers to their local templates/legal-agreement.css as the Constitutional/Shareholder-Agreement base. This vault already has paper.semantic.legal-agreement.* tokens — but they back the unrelated legal-subscription-agreement component (accredited-investor fill-in booklets). Same name, two different document families, two different archives' independent naming choices colliding by coincidence. This component's constitutional-agreement variant deliberately does not bind to the pre-existing legal-agreement.* tokens for this reason — see oq-1 on the recipe.
• Two real overlaps with legal-agency-suite, flagged not merged. That component's schedule-cover variant and its proposal-letter / mou-engagement-letter variants cover essentially the same ground as this component's schedule-exhibit and letter variants. Both components are now live with overlapping scope — this needs a reconciliation decision (which register is authoritative, or do they merge) that neither this session nor project-documents' original request resolved. Recorded as oq-2/oq-3.
• Most token values are provisional by design, not by omission. project-documents' own request explicitly defers CSS delivery ("Commercial first, from JW9... [others] to follow as we work each type"). This component's paper.semantic.paper-legal.* DTCG tokens therefore only bind the one thing stated with confidence (Tinos font family) plus generic rule weights already proven safe to reuse across the Paper pillar; every variant's heading-form/numbering/cross-ref rule lives instead in the separate paper-legal-conventions block, which is deliberately non-DTCG-typed string data (mirroring the existing number-format block's own precedent for the same kind of non-measurement convention data).
• preliminary-instrument is genuinely new ground. Unlike the other four variants, no existing component in this vault covers MOU/LOI/term-sheet documents at all — no reconciliation question needed there.

What a downstream consumer should do

1. Classify the document into one of the 5 categories using the recipe's variants array descriptions.
2. Pull that category's heading-form / article-word / cross-ref-capitalization rule from paper.semantic.paper-legal-conventions.<variant>.
3. Apply the 9 family-wide drafting rules (paper.semantic.paper-legal-conventions.drafting-rules-family-wide) regardless of category.
4. For CSS: check whether project-documents has delivered the category's templates/<name>.css yet (only commercial-agreement is in progress as of this writing); if not, the convention rules above still apply even before CSS exists — draft to the rule, not to a stylesheet that doesn't exist yet.
5. If the category is schedule-exhibit or letter, also check legal-agency-suite's schedule-cover / proposal-letter / mou-engagement-letter variants before building anything net-new — the overlap is unresolved, and building against both independently would create a third, worse inconsistency.