Traceability codes

The machine-readable contracts under contracts/ tag some entries with a short code such as LANG-05 or QA-07. The codes are traceability ids: the validators require one wherever a feature is blocked, a limit is known, or an exclusion is deliberate (tools/quality/feature-operation-matrix.mjs accepts ^[A-Z]+-\d{2}$), so a reader can see that the state was decided rather than forgotten. They are not ticket numbers in an external tracker, and the source code and guides describe behavior in plain words rather than by code.

Families

Family	Meaning	Where it appears
LANG-nn	A language decision: syntax accepted, rejected, or limited by the Portable profile (for example LANG-05 multidimensional arrays, LANG-10 bitfield storage rules, LANG-15 alignment and offset overrides, LANG-16 compiler/ABI behavior).	feature-operation-matrix.json limitations and exclusions
API-nn, IR-nn, PERF-nn, SAF-nn, COR-nn	Managed API, compiled intermediate representation, performance, safety-limit, and core-behavior decisions that bound a feature or an operation.	feature-operation-matrix.json contracts and known limits
QA-nn	A quality gate: QA-03 compiler-differential fixtures, QA-04 the managed fuzz corpus, QA-07 the frozen managed and browser API baselines, QA-08 the non-web release budgets.	feature-operation-matrix.json, contracts/api/*/manifest.json, contracts/performance/non-web-rc1.json
DOC-nn	A documentation contract: DOC-01 is the canonical Portable reference and its manual fixtures.	feature-operation-matrix.json
Performance-plan items (E1.x, E2.x, E3.x) and architecture-plan items (AP-x.y)	Steps of two completed improvement plans, kept only in the history entries of the API baselines and the browser contract, where they explain why a recorded change was made.	contracts/api/managed-rc1/manifest.json, contracts/api/browser-rc1/contract.json

Reading a tagged entry

Each tagged entry carries its own explanation next to the code (a summary, rationale, syntax, or change text), so the code never has to be looked up to understand the entry. When a limitation is lifted, remove the entry and its code together; when a new deliberate limit or exclusion is recorded, tag it with the family that owns the decision and the next unused number.