About: http://webisa.webdatacommons.org/83751732

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	Clearly a blog post is called for, but, whilst you wait for a post that will never arrive, here is a link to some examples that should open your eyes to what is possible with pdftk.
http://www.w3.org/ns/prov#wasQuotedFrom	chrisjrob.com