rdf:
http://www.w3.org/1999/02/22-rdf-syntax-ns#
rdfs:
http://www.w3.org/2000/01/rdf-schema#
owl:
http://www.w3.org/2002/07/owl#
dc:
http://purl.org/dc/elements/1.1/
foaf:
http://xmlns.com/foaf/0.1/
skos:
http://www.w3.org/2004/02/skos/core#
