The second sovereignty perimeter: the condition in which an entity is preferentially retrieved for category-defining queries — ‘what you do’ authority. Domain sovereignty requires industry-specific corroboration, category-defining content, and sustained attribution rate in domain queries. More contested than identity sovereignty because competitors occupy the same domain. Domain sovereignty is measured through domain-specific retrieval preference: when AI systems are asked industry questions, is your entity among those cited? Domain sovereignty without vocabulary sovereignty is presence without differentiation.