<http://webisa.webdatacommons.org/199828862> <http://www.w3.org/ns/prov#wasQuotedFrom> <mozilla.org> . <http://webisa.webdatacommons.org/199828862> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.w3.org/ns/prov#Entity> . <http://webisa.webdatacommons.org/prov/214380084> <http://www.w3.org/ns/prov#wasDerivedFrom> <http://webisa.webdatacommons.org/199828862> . <http://webisa.webdatacommons.org/199828862> <http://www.w3.org/ns/prov#value> "For the objects other than Bug, some fields are marked Optional to show that they are not always present." .