element may not have both content and rdf:resource value.  element must have either content or rdf:resource value. pcv:Descriptor may not have both rdf:ID and rdf:about attribute values. pcv:Descriptor must have rdf:ID or rdf:about attribute values. Only one contentLength subelement allowed. Only one creationTime subelement allowed. Only one expirationTime subelement allowed. Only one modificationTime subelement allowed. Only one publicationTime subelement allowed. Only one receptionTime subelement allowed. Only one releaseTime subelement allowed. Section 3.6 of PRISM 1.1 spec: rdf:resource attribute of prl:usage element must have #none, #use, #notApplicable, or #permissionsUnknown as value. (rdf:resource value "")