knowledge: spec-document gates (4 axes + controls) and non-ASCII grep matching

[dch0202-rsquare]

Knowledge flush — 4 insight(s)

Queue drained: 4 pending candidates from 2 sessions (19484655…, dd51281c…,
harvested 2026-07-30). They land as 2 pages — three candidates describe one
situation (gates on a spec document) and merge into a single page; the fourth is a
distinct mechanism (Unicode text matching) and gets its own.

#	Candidate (trigger)	Target
1	Fixing a grep gate for a document that does not exist yet	qa/document-verification/spec-document-gates.md (§Do this 1)
2	Verifying an RFC/API-spec's requirements with grep gates	same page (§Do this 3, four axes)
4	Prose-document checklist that keyword checks pass vacuously	same page (§Do this 3–4, modality/polarity + fail-closed)
3	grep/regex over Korean text, stem-prefix pattern	platforms/environment/unicode-text-matching.md (new page)

Verified best-practice

Candidates 1, 2, 4 — gates on a specification document → confidence: field-tested

Claim. A token-existence grep is not sufficient evidence that a document meets a
requirement; gates need a positive control (a conforming sibling the pattern must
match), a negative control (a mutated copy it must reject), four check axes
(structure / modality+polarity / closed-set completeness / cross-reference), and
fail-closed behaviour when the anchor is missing.

Sources checked. Each mechanism is grounded in a tool or spec that implements it:

Directive	Source	What it says (checked, not assumed)
Positive and negative control per gate	eslint.org custom-rule-tutorial (fetched)	Verbatim: "RuleTester requires that at least one valid and one invalid test scenario be present."
Structure of a checker's test cases	eslint.org nodejs-api (fetched)	RuleTester#run() takes valid + invalid arrays; invalid cases assert the expected error count
Mutants prove detection, coverage does not	testing.googleblog.com mutation testing	Inserting faults and requiring failure measures whether checks detect bugs (already cited by testing-quality-tests-that-cannot-fail)
MUST→SHOULD demotion changes the requirement while keeping every keyword	RFC 2119 (fetched)	MUST = "an absolute requirement of the specification"; SHOULD = there "may exist valid reasons … to ignore a particular item"
Cross-reference axis is a real check class	docs.vale.sh/checks/conditional (fetched)	Verbatim: "Ensures that the existence of 'first' implies the existence of 'second'."
Count + scope, not bare existence	docs.vale.sh/checks/occurrence (fetched)	Enforces "the maximum or minimum number of times a particular token can appear in a given scope" (scope: sentence)
Table structure gets parsed, not grepped	markdownlint MD056	Flags tables whose rows disagree with the header column count
A delimiter count is not a parse	markdownlint issue #1206	MD056 counts pipes inside backticks as separators and misreports — the failure mode of approximating a parse

How verified. Every ESLint/Vale/RFC quote above was fetched from the primary
source in this session, not recalled. The composite methodology (the four-axis
framing and its ordering) comes from the two harvested sessions, where an
independent auditor built tampered copies that a 16-gate existence checklist
accepted (5 of 8 passed all 16, including one with a row deleted from a 5-row
type enum) and, after the axes were added, 32/32 mutants failed their designated
check while the intact document passed 62/62.

Resulting confidence: field-tested, deliberately not verified. Each
individual directive is doc-backed, but the composite rule's evidence is in-house
session experience a reader cannot re-run, so the page carries a Field context
section stating that provenance instead of claiming external verification.

Candidate 3 — Unicode text matching → confidence: verified

Claim. A stem-prefix pattern silently returns 0 hits on precomposed text
(아니 is not inside 아닌), and grep applies no canonical equivalence, so an
NFC pattern misses NFD data entirely.

How verified — reproduced locally (macOS 15 / APFS, grep 2.6.0-FreeBSD, Python 3.13, 2026-07-30):

NFC 아닌 = U+C544 U+B2CC     NFC 아니 = U+C544 U+B2C8     substring? False
NFD 아닌 = U+110B U+1161 U+1102 U+1175 U+11AB              substring? True   ← form-dependent
grep -c '아니' <NFC file> → 0      grep -c '아닌' <NFC file> → 1   (same line)
grep -c -f <NFC pattern> <NFD file> → 0      -f <NFD pattern> → 1

The NFC/NFD asymmetry was not in the harvested candidate; the reproduction
surfaced it, and the page states it because it decides whether the naive pattern
fails at all. A second reproduction (creating an NFC-named file, listing it, and
opening it by both forms) confirmed APFS returns the name as written and resolves
either form — matching Apple's documented behaviour rather than the folklore that
macOS always decomposes.

Sources checked.

• UAX #15 (fetched) — Hangul syllables have special full-decomposition rules and are maintained under all normalization forms; canonically equivalent strings have different binary representations unless normalized.
• Unicode 16.0 core spec, chapter 3 — §3.12 Conjoining Jamo Behavior: 11,172 precomposed Hangul syllables from SBase = U+AC00, algorithmic L/V/T decomposition.
• Apple File System Guide FAQ — APFS preserves the file name's normalization and is normalization-insensitive via hashes of the normalized form; HFS+ stores the normalized form.
• POSIX grep — matching is specified by regular-expression rules over input lines; no canonical-equivalence folding.

The candidate's own note that its first diagnosis ("BSD grep ERE multibyte bug")
was wrong is preserved as behaviour, not blame: the page's edge-case row says to
dump code points before concluding the text is absent.

Nothing left unverified. No candidate was dropped.

Existing-layer check

Pages read in full: INDEX.md, AGENTS.md, templates/page.md,
skills/wiki-ingest/SKILL.md, wiki/qa/index.md, wiki/testing/index.md,
wiki/platforms/index.md, wiki/debugging/index.md,
wiki/testing/quality/tests-that-cannot-fail.md, wiki/qa/process/release-gates.md,
wiki/qa/process/acceptance-criteria.md (frontmatter + structure),
wiki/platforms/environment/timezone-and-locale.md,
wiki/platforms/filesystems/paths-case-and-line-endings.md.
Repo-wide greps for grep, unicode|normali[sz]|codepoint|multibyte|NFC|NFD,
and specification|RFC|design doc|acceptance criteri to find any page already
holding this material.

Overlap candidate	Verdict
testing-quality-tests-that-cannot-fail	Closest neighbour, not a duplicate. It owns "prove a test can fail by mutating the code"; the new page owns "prove a document gate can pass and can fail". Same principle, different artifact and different failure table. Linked both ways, and the new page's edge-case table routes code deliverables back to it.
qa-process-release-gates	Human release checklist (suite green / smoke / regression / rollback). No overlap with automated checks on a document's text. Left untouched.
qa-process-acceptance-criteria	Adjacent: it defines testable criteria for a ticket; the new page verifies a document against them. Back-link added; the new page's "document deliberately relaxes a requirement" row points at it.
platforms-environment-timezone-and-locale	Covers locale-dependent casing and collation (Turkish İ/ı, LC_COLLATE) — the environment as hidden input. Normalization form is a property of the data, not the environment, and the page is already 81 lines with a different "load when". Kept separate, back-linked.
platforms-filesystems-paths-case-and-line-endings	Covers case-collisions and CRLF; mentions path normalization only as "use the platform's path API". Does not cover Unicode form. Back-link added.
platforms-tools-bsd-vs-gnu-cli	Owns userland flag differences. The new page cites it inline for the multi-byte character-class caveat rather than restating it.

Conflicts flagged: none. No existing directive contradicts either new page.

Reciprocal related: links added to testing-quality-tests-that-cannot-fail,
qa-process-acceptance-criteria, platforms-environment-timezone-and-locale, and
platforms-filesystems-paths-case-and-line-endings.

Routing decision

1. qa / new category document-verification / spec-document-gates.md

• Domain — qa over testing. INDEX.md scopes testing to automated test
  code for software behaviour; the artifact here is a written deliverable and the
  question is "does it meet its acceptance criteria, and is the gate that decides
  that trustworthy" — which is qa's remit (acceptance criteria, gates). Two of the
  four candidates self-declared qa; the third declared testing and is routed
  with them because it is a directive about the same gates.
• New category justified. Existing qa categories are process (human release
  workflow), environments (staging parity), bug-reports, exploratory — none
  covers automated verification of an artifact. Folding it into process would put
  a script-authoring page among human-workflow pages and blur that index's routing
  lines. document-verification is where doc linting and link checking will also land.
• Merged 3 candidates into 1 page per "one case per page": all three answer the
  same situation (authoring/reviewing gates over a spec document) — candidate 1 is
  the control step, candidate 2 the what to check step, candidate 4 the
  polarity + fail-closed step. Splitting them would produce three pages sharing one
  "load when" line, which is what the merge-before-create rule exists to prevent.

2. platforms / existing category environment / unicode-text-matching.md

• Domain — platforms over qa (the candidate's own hint): the mechanism is
  text representation and its OS/producer-dependent form, not release quality. The
  platforms index already owns "hidden environment inputs" and cross-OS filesystem
  behaviour, and environment/ is the sibling of timezone-and-locale, the existing
  page for text operations that behave differently than assumed.
• No new category — environment fits, so none was created.
• Cross-linked to the qa page so a doc-gate author writing a Korean pattern is
  routed here, and back so a 0-hit debugger reaches the gate-design rules.

Plumbing updated

wiki/qa/index.md (new category block + route-line scope), wiki/platforms/index.md
(page row + intro scope), INDEX.md (both domain route lines), log.md (2 ingest
entries). Checked before commit: both pages under the 120-line body limit (77 / 54),
every related: and inline [page-id] resolves, both pages listed in their domain
index, no banned vague qualifiers, no prohibition without a paired replacement.

Decision Log

• 의도 — 큐 4건을 드롭 없이 위키에 넣되 중복 페이지를 만들지 않도록 3건을 한
  페이지로 병합하고, 각 지시문을 1차 출처로 검증했다. 하베스트된 주장을 그대로 옮기지
  않고 ESLint·Vale·RFC 2119·markdownlint 원문을 실제로 열어 인용했다.
• 배제 — ⓐ 4건을 4페이지로 쪼개는 안(“one case per page” 위반, load-when 라인이
  겹침) ⓑ Unicode 건을 timezone-and-locale에 병합하는 안(그 페이지는 환경이 입력인
  경우를 다루고 정규화형은 데이터의 속성 — 트리거가 다름) ⓒ 문서 게이트 페이지를
  qa/process에 넣는 안(사람 프로세스 페이지 사이에 스크립트 작성 지침이 섞임)
  ⓓ 복합 방법론에 verified를 부여하는 안 — 개별 지시문은 출처가 있으나 4축 조합의
  근거는 사내 세션이라 field-tested로 낮추고 그 사실을 페이지에 명시.
• 리뷰포인트 — ① 새 카테고리 qa/document-verification 신설이 과한지(대안: process
  편입) ② 후보 3건 병합 경계가 맞는지 ③ field-tested 등급 판단 ④ Unicode 페이지의
  NFC/NFD 비대칭은 원 후보에 없던 내용으로 이번 재현으로 추가된 것 — 원 후보 취지를
  넘어서는지.

Cross-Check: 각 지시문을 1차 출처 원문 fetch로 대조(ESLint RuleTester 문장·RFC 2119
MUST/SHOULD 정의·Vale conditional/occurrence 설명·UAX #15·APFS FAQ), Unicode 주장은
로컬 재현 2종(코드포인트 덤프 + grep 4회, APFS 파일명 생성/조회)으로 실측. 이번 세션은
서브에이전트 사용이 배제되어 독립 에이전트 적대검증은 돌리지 않았음 — 검증은 출처
대조와 재현에 근거한다.