docs-lint enforces the writing style guide's machine-checkable rules: an em dash inside a list item, a lower-case letter opening a list lead-in after its colon, and a capital letter after a semicolon are flagged as findings, with code spans and fenced blocks masked, so the canonical style guide's machine-enforceable subset is a shipped gate rather than a review habit — and the guide marks a rule machine-enforced only once its lint ships

⚠️ Superseded by ADR-54 (the em-dash core shipped as the punctuation/em-dash-in-list-item banned token via iss-2608280706531199; corpus evidence showed the casing rules have zero true positives with unclosable false-positive classes, so they are review by nature and the staged lint is not built; the continuation-line residual has zero instances and reopens as a fresh intent on first regression). Retired 2026-08-28 from drafts/ at the planning interview — never planned, never specced. Preserved as historical record per the supersession lifecycle.

Typed links: refines the docs-lint rule family (native banned-token and structural rules; this adds a prose-style family). The canonical style guide lands at docs/reference/writing-style.md in the same change that files this draft; the guide labels these rules review until this intent ships (enforcement-claims-are-facts).

Press Release

Seeded from a quoted-text intent capture. Expand into the full press-release narrative before planning.

Why This Matters

The style guide's punctuation rules (no em dash inside a list item — use a colon; a capital letter after a colon; lower case after a semicolon) are mechanical enough for a deterministic check, and a rule that is checked by machine stays followed long after review attention moves on. The enforcement-claims-are-facts principle requires the guide to label each rule honestly; shipping this lint is what flips the punctuation labels from review to machine-enforced.

SOTA

• Native docs-lint now; Vale is the named preferred future upgrade path (maintainer ruling, 2026-08-22). The rules land as native docs-lint checks — no new dependency, same gate as the existing families. Vale (the open-source prose linter whose packages ship whole style guides as configuration) is recorded here as Related/SOTA: if abcd ever wants full-guide enforcement rather than a house subset, adopting Vale beats reimplementing it. That adoption is not this intent.
• Adopt-not-author exploration (run at the SOTA pass): Candidates for adopting an existing open-licensed writing guide rather than authoring more house rules — the Google developer-documentation style guide, the Microsoft Writing Style Guide, the GitLab documentation style guide, and the errata-ai/styles packages that ship guides as Vale configurations. Design direction: An abcd-managed repo chooses among guides via its .abcd/rules.json override — the existing per-repo mechanism; point, don't copy. Print references the maintainer rates are copyright-bound: consult-only via the private sources corpus if acquired, never redistributed or quoted at length; open-licensed guides are the adoptable ones.

Acceptance Criteria

BDD format, per the itd-1 discipline.

• Given a docs page whose list item contains an em dash outside any code span, when abcd docs lint runs, then an em-dash-in-list-item finding names the file and line — and a test watched the rule fail before the change and pass after.
• Given a list lead-in whose text after the colon opens lower-case, or a clause after a semicolon opening with a capital, when the lint runs, then the case rule flags it.
• Given the same tokens inside a code span, fenced block, or frontmatter, when the lint runs, then no finding is emitted (masking).
• Given the lint ships, when the style guide is read, then the punctuation rows are labelled machine-enforced with the shipped rule ids, and no rule anywhere in the guide claims enforcement its lint does not perform.

Open Questions

• Whether the case-after-colon rule is scoped to list lead-ins only (the low-false-positive core) or extended to running prose, where legitimate exceptions multiply.
• Whether an adopted open-licensed guide (see SOTA) replaces parts of the house guide, and how a managed repo's .abcd/rules.json names its chosen guide.

Audit Notes

Empty. Populated by intent-auditor when intent moves to shipped/.