docs: citation, heading and Mermaid forms that depart from documentation.rst #2561

From the 2026-11-01 conventions audit, re-verified on 73add05a3. Each item breaks a written documentation.rst rule; the heading scans were samples, not parses.

• "Format and Mechanics": :issue: roles that name pull requests: pep.rst, "Deterministic Construction Arguments" (fix(ipv6_ext): stop the base make's keywords leaking into subclasses that ignore them (#2286) #2358) and "Delivery Sequence" (feat(protocols): add the IP_Pseudo pseudo-protocol for the IP pseudo-header (#2471) #2479, "for its pseudo-header checksum"); protocol-layer-placement.rst, "Things That Will Look Like Mistakes" (fix(foundation): check every register_protocol_code key before registering any (#2268) #2343); sentinel-convention.rst, "Naming a Sentinel" (refactor(corekit)!: move the byte-order field helpers into corekit (#1711) #1715); const-vendor-pairing.rst, the opening ruling (feat(application): implement TLS/SSL and DTLS record layer + handshake framing #2441); the doc-comments on LINE and Vendor.PROTO_DEST in pcapkit/vendor/default.py (refactor(foundation): declare each registry's code kind as a class attribute, not a module table (#2343) #2392). tests/project/test_docs_issue_pr_roles_1103_unit.py checks only bare numbers and hand-written links, so nothing enforces this half.
• "Paraphrasing a Ruling" (name the issue, not the pull request): :pr: in protocol-family-grouping.rst, const-vendor-pairing.rst, reassembly-integration.rst ("Compliance, Measured", "The DTLS reassembly work on"), process.rst ("The PEP Discussion, Kept Current"), workflows.rst ("Workflow Scripts" and "Workflow Lint") and releasing.rst ("Recovery"). process.rst's "The PEP Discussion, Kept Current" cites chore(docs): centralise changelog entries for unreleased versions #2483 for a ruling given only on that thread (it closes chore(docs): centralize 1.6.0 changelog updates in one place, not per-feature-PR #2449), so record that instead of swapping the role; refactor(foundation): route DTLS reassembly via toolkit and analysis (#2496) #2528 rewrites the "The DTLS reassembly work on" paragraph in reassembly-integration.rst.
• workflows.rst carries hand-written tracker links to ci(python): GraalPy's unit tier stops on an xdist worker MemoryError under the 2 GiB per-process heap #1753, ci(experimental): skip or stop superseded runs instead of cancelling them, so commits are not marked red #1938, ci: stop repeating text-only PR pin tests on every main unit leg #1954, test: sort the remaining GraalPy-only failures into defects and gates #1963, ci: PyPy workers on the ALL tier grow until they are OOM-killed #2005, ci: Python 3.14t and GraalPy experimental legs produce no JUnit XML #2073 and ci: Containment summary reports a superseded stop as 'tests exited 0' #2077 and a bare #1962; the 1103 test passes only through its ALLOWED set (other tests pin those strings), which documentation.rst does not mention.
• "Heading Case and Shape", finite verbs: warnings.rst "How a Warning Is Reported", logging.rst "What DEBUG Will Tell You", ext.rst "What's in for Protocols?" (a non-how-to question; its casing is fine); protocol-layer-placement.rst "Things That Will Look Like Mistakes" is borderline.
• Lowercase content words: const/tcp.rst and vendor/tcp.rst "Multipath TCP options"; const/vlan.rst and vendor/vlan.rst "Priority levels defined in IEEE 802.1p"; const/mh.rst and vendor/mh.rst "... Type field in the Mobility Header"; the "... version N" titles of ipv4.rst, ipv6.rst, igmpv1.rst, igmpv2.rst, igmpv3.rst, l2tpv2.rst, sslv2.rst. The page exempts no verbatim registry title.
• "Mermaid for Flows", letter only: the SUFFIXED and BARE nodes of mint-criterion.rst's decision graph (_unregistered_member) and the VALUE node of registry-protocol.rst's get() graph under "Failed-Lookup Exceptions" (_validate_value) leave a leading underscore unescaped; they render plain under CommonMark, and Mermaid's own parser was not run.

Fix: cite what each number is (the issue the PR closes: #2286, #2471, #2268, #1711; #2441 and #2392 close none, so say where the ruling sits); rename or re-case the headings per the verb/gerund line; escape the underscores; tighten the 1103 test to resolve each role's kind, and state its ALLOWED set on the page. Sweep references to every renamed heading ("Renaming a Heading").
Blocked: #2519 (warnings.rst), #2521, #2528, #2537, #2540, #2542, #2543 and #2544 edit pages above; unblocks when all eight merge (gh pr view <n> --json state -q .state prints MERGED).