PropertyValue
http://www.w3.org/1999/02/22-rdf-syntax-ns#type
http://www.w3.org/ns/prov#value
  • It may be provided by pasting the message into the server, and it may be provided automatically, in response to the user opening the message, or by clicking on a link, a button or other operator included in, or in conjunction with, the message.
http://www.w3.org/ns/prov#wasQuotedFrom
  • google.com