$Revision: 1.3 $ The class of Thing. String Integer Uniform Resource Indicator There is already "URL" in Protege under :THING -> RDF Helper -> URI It seems to conflict if we use "URL" here. Time The class of Place. 1 Address String 1 1 1 1 1 1 Person related to IT Talks 1 1 1 1 1 1 1 1