# Reachability Benchmark · Governance & Maintenance

## Roles
- **TAC (Technical Advisory Committee):** approves material changes to schemas, truth sets, and scoring rules; rotates quarterly.
- **Maintainers:** curate cases, review submissions, run determinism checks, and publish baselines.
- **Observers:** may propose cases and review reports; no merge rights.

## Release cadence
- **Quarterly update window:** publish new/updated cases and hidden test set refreshes once per quarter.
- **Patch releases:** critical fixes to schemas or scorer may be shipped off-cycle; must remain backward compatible within `version: 1.x`.

## Hidden test set
- A reserved set of cases is held back to prevent overfitting.
- Rotation policy: replace at least 25% of hidden cases each quarter; keep prior versions for audit.
- Hidden cases follow the same determinism rules; hashes and schema versions are documented internally.

## Change control
- All changes require:
  - Schema validation (`tools/validate.py`).
  - Deterministic rebuild (`tools/build/build_all.py` with `SOURCE_DATE_EPOCH`).
  - Updated truth files and baselines.
  - Execution log entry in `docs/implplan/SPRINT_0513_...` with date/owner.
- Breaking changes to schemas or scoring rules require TAC approval and a new major schema version.

## Determinism rules (global)
- No network access during build, analysis, or scoring.
- Fixed seeds and sorted outputs.
- Stable timestamps via `SOURCE_DATE_EPOCH`.
- Telemetry disabled for all tools.

## Licensing & provenance
- All public artifacts are Apache-2.0.
- Third-party snippets must retain attribution and be license-compatible.
- Each release captures toolchain hashes (compilers, runners) in the release notes.

## Incident handling
- If a nondeterminism or licensing issue is found:
  1) Freeze new submissions.
  2) Reproduce with `ci/run-ci.sh`.
  3) Issue a hotfix release of truth/baselines; bump patch version.
  4) Announce in release notes and mark superseded artifacts.