# DEFAULT_REGISTRY_LANG

**Kind:** Constant

**Source:** [`atloria-monorepo/apps/api/src/docs-repo/sidecar.ts`](https://github.com/sherkety/atloria/blob/main/atloria-monorepo/apps/api/src/docs-repo/sidecar.ts#L105)

B6 (docUuid, lang) registry keying — a PERSISTED-FORMAT MIGRATION done inside the parse
path, not a rewrite of the ledger:

  • lang === 'default'  → the key is the BARE docUuid — byte-identical to every entry
    written before B6, so an existing ledger round-trips without a single changed key
    (no fabricated commit, no history churn).
  • any other lang      → `docUuid@<lang>`. '@' is not a uuid character and not produced
    by any slug/scope, so the split is unambiguous; parseRegistryKey treats a key with
    no '@' as the legacy form (lang='default').