# YSD-0133 — Typed cross-reference vocabulary and governance

- **Status:** approved (2026-07-18)
- **Priority:** P0 EXT — blocking (production rollout gated via YSD-0139)
- **Decision owner:** @GreyChimp
- **Drafted:** 2026-07-18 by Claude Code (claude-fable-5)
- **Approval:** approved as recommended by @GreyChimp on 2026-07-18; outcome
  recorded in decision-log.json; review by 2027-07-18

## Question

Which typed relation vocabulary, directionality, review states, and identity
rules govern cross-references?

## Recommendation

Adopt the Section 2.6 relation set (identity, similarity, contrast, influence,
analogy, shared function, transformation, sequence, evolution, support,
contradiction, counterexample, avoidance, derived principle, informed decision)
with per-relation directionality/inverses/symmetry (YSD-2152); review states
from YSD-2005 (suggested/accepted/corrected/contested/rejected/superseded);
identity is always a reviewed claim — visual/audio similarity never auto-merges
entities (YSD-2155); taxonomy changes go through versioned vocabulary releases
with migration rules (YSD-2035).

## Options considered

- Free-form string relations — rejected: untypeable, unfilterable, and
  unreviewable.
- Auto-merge on high similarity — rejected: YSD-2155 prohibition.

## Consequences

- Section 2.6 implements; Gate 16 (YSD-18145) proves provisional-until-review
  behavior.

## Machine-enforced outcome (once approved)

Relation-kind enum in contracts; graph invariants (YSD-2159) reject invalid
kinds; identity merges require review records.