ADR-026: World model version as unit of authority

Status: Accepted (2026-04-20)

Source: migrated from planning/swms-decisions.md ADR-036 as part of SPEC-270.

Context

A system card anchors its claims to a specific world model version. Rules may be corrected in subsequent versions. A question arises: do rule corrections retroactively invalidate prior system cards generated against the prior version?

If yes, the system needs a restatement protocol and a mechanism to propagate corrections back through the card history. If no, the system needs a clear principle explaining why prior cards remain valid and a mechanism that documents the corrections without disturbing the prior cards. The design interview resolved this.

Decision

The world model version is the unit of authority. A published version is authoritative for that version. System cards generated against a prior published version are not retroactively invalidated by corrections in subsequent versions. Corrections are documented in release notes accompanying the correcting version. Release notes are the restatement mechanism.

• A published world model version is authoritative for that version. Claims made in system cards against that version are correct statements about performance against the published standard at that version.
• Rule corrections discovered in subsequent versions are documented in release notes accompanying the correcting version.
• System cards generated against a prior published version are not retroactively invalidated. They remain correct statements about performance against the standard as published at that version.
• Recertification against a new version is a separate decision by the subject, not an automatic requirement driven by the correction.
• Release notes are the restatement mechanism. They live with the world model, not with the system card.
• No separate restatement protocol is required.

Consequences

• Release notes are a first-class artifact of the world model, not an auxiliary document. They carry the corrections record that would otherwise need to propagate through system card history.
• System card history is stable. Prior cards are not mutated when subsequent versions correct rules; they stand as historical artifacts of performance against the standard at the time.
• Recertification is an explicit decision. A subject choosing to recertify against a new version produces a new card at that version; the prior card remains on the record.
• The cross-period comparability path through authority_version (ADR-015) is preserved. Readers comparing cards across versions reconcile the differences through the release notes of the intervening versions.
• The design does not require a restatement protocol, a retroactive invalidation mechanism, or a card mutation pathway. The absence of these mechanisms is a deliberate choice following from the version-as-authority principle.