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ADR-0001 — R-M-12 stands

Status: accepted. Sponsor decision, 2026-09-22, in review of DECISIONS-0001 tier 1 items 1 and 5.

Decision

R-M-12 stands. Native extension points — type identifiers, predicate types, tags, header parameters — are identified relative to a defining principal, as a (key, local label) pair. The native model depends on no centrally allocated registry for their meaning.

It is promoted out of a requirement row into its own architecture document, ARCH-0002, because it is a cross-cutting principle rather than a constraint on one mechanism, and because it is the most novel claim the project has:

SDSI localized principal names. Nobody localized type names.

Consequences

  • ARCH-0002 becomes the home for key-relative naming and everything that follows from it. ARCH-0001 references it; the requirement row is replaced by that reference on acceptance of v0.2.0.
  • DEC-002 is constrained. CBOR tags and COSE header parameters are IANA allocated, so they are interchange, not native. Proposed option 5 — CBOR data model without registry dependence — remains on the table; option 2 as originally written does not.
  • DEC-004 and DEC-007 are constrained the same way: a tag language and a rendering vocabulary are both key-relative.
  • Registry identifiers may appear at interchange boundaries, and such mappings are documented as lossy per R-I-01.

Alternatives rejected

Keep R-M-12 as a requirement row in ARCH-0001 §5. Rejected: it constrains three open decisions at once and carries argument that does not fit a table cell.

Use registry private-use ranges instead. Rejected: private use gives escape from a registry, not a namespace. Two parties independently using the same private label collide with nothing to disambiguate them, because no principal is attached. The identifier stays global; only its allocation becomes informal.

Evidence

  • IANA allocation policies for CBOR tags (RFC 8949 §9.2) and COSE header parameters (RFC 9052 §11.1), verified 2026-09-16.
  • The independent re-invention of a PICS-style vocabulary inside draft-mih-scitt-agent-action-capsule-02, showing the pattern is undersupplied rather than unwanted.