First perimeter: reliable entity identification by AI systems. Build through: KGMID assignment, schema.org Person/Organization markup, Wikidata item, consistent NAP across directories, comprehensive sameAs linking. Test with identity queries (“Who is [entity]?”). Target: accurate, confident response with correct disambiguation. Prerequisite for domain/vocabulary sovereignty. Easiest perimeter to establish. Most organizations have or are close to identity sovereignty. Maintain through schema consistency and quarterly disambiguation testing.