# Decision 0005: Phase 0 Source of Truth

Status: `Locked`

## Context

`docs/phase0_checklist.md` began as an options menu. Once the Phase 0 decisions
were locked, the project needed one clear rule for which document is
authoritative.

## Decision

Decision records under `docs/decisions/` are the source of truth for locked
Phase 0 choices.

`docs/phase0_checklist.md` remains useful, but only as a progress and navigation
document. When a checklist item is locked, it should point to the corresponding
decision record.

## Consequences

- The checklist can stay concise.
- Locked decisions are not duplicated as prose in multiple places.
- Future changes to posture, BIOS policy, milestone definition, or validation
  policy should update the decision records first.