Proposal: Identifier Scope and External Links

Status

Accepted for OAA 1.0

Summary

Define identifiers by record type and archive-local scope. Treat external links as associations rather than automatic merge keys.

Motivation

Different record types can safely reuse the same opaque identifier. Multiple artworks can also legitimately refer to the same external publication or source record.

Specification Changes

• Gallery IDs MUST be unique among galleries in an archive, and artwork IDs MUST be unique among artworks in that archive.
• File IDs MUST be unique within their containing artwork.
• The same identifier string MAY occur in different record-type scopes or as a file ID in different artworks.
• OAA IDs are opaque and archive-local; the format does not assert global identity or stability across independent exports. A stronger unchanged-import/export preservation guarantee belongs to the deferred preservation profile, not the 1.0 core identity contract.
• Readers MUST NOT treat a shared external link alone as an instruction to merge artwork records.
• Readers MUST NOT reject unknown external link providers.
• Redundant external links MAY produce a warning, but repetition alone MUST NOT make an archive invalid. Do not impose archive-wide uniqueness on a (provider, id) pair.

Compatibility Impact

This clarifies ambiguous identifier-uniqueness language. It supersedes the earlier review suggestion to reject duplicate external provider-and-ID pairs; that rejection is not part of the accepted design.

Examples

A gallery and artwork can both use 001. Two artworks can link to the same publication record while remaining distinct artworks. Repeating an identical external link is redundant, not an identity collision.

Open Questions

None for this decision. Cross-archive matching and application merge policies remain outside the base format.