OWLOntologyID
@interface OWLOntologyID : NSObject <NSCopying>
An object that identifies an ontology.
Since OWL 2, ontologies do not have to have an ontology IRI, or if they have an ontology IRI then they can optionally also have a version IRI. Instances of this OWLOntologyID class bundle identifying information of an ontology together. If an ontology doesn’t have an ontology IRI then we say that it is “anonymous”.