(2014-06-13) Bernard Vatant: OWL is used alone or along with RDFS by many LOV vocabularies. The formal schema available from the namespace is older than the matching W3C Recommendation, if the owl:versionInfo is correct.
(2015-07-11) Ghislain Atemezing: Annual review done! Be aware of this note: "This ontology SHOULD NOT be imported into OWL ontologies. Importing this file into an OWL 2 DL ontology will cause it to become an OWL 2 Full ontology and may have other, unexpected, consequences."