is identifier of OBO_REL:is_a Subject A can either be a concept that is an 'Identifier', or an entity outside of an ontology (or an ontology concept in a role of an entity being semantically annotated) that is an 'Identifier' or is in the role of an 'Identifier'. Object B can be any concept or entity outside of an ontology. In EDAM, only 'is_identifier_of' is explicitly defined between EDAM concepts (only 'Identifier' 'is_identifier_of' 'Data'). The inverse, 'has_identifier', is not explicitly defined. 'A is_identifier_of B' defines for the subject A, that it is an identifier of the object B. false false false false Data Identifier