Common base type for all types that have unique identity. If id is provided and is not in proper URN syntax then it is used for linkage within document and is ignored by the registry. In this case the registry generates a UUID URN for id attribute. id must not be null when object is retrieved from the registry. Mapping of the same named interface in ebRIM. Common base type for all types that have unique identity. If id is provided and is not in proper URN syntax then it is used for linkage within document and is ignored by the registry. In this case the registry generates a UUID URN for id attribute. id must not be null when object is retrieved from the registry.