- Admin GraphQL API adds MarketRegionSubdivision type for sub‑region (state/province) markets, accessible via market.conditions.regionsCondition.regions.
- Deprecated market.regions may omit subdivisions; apps should migrate to the new field for accurate sub‑region membership.
- Only shipping currently supports sub‑region markets—discounts, catalogs, themes, and metafields are unsupported and will trigger validation errors.