About: http://webisa.webdatacommons.org/111630187

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	I say almost because you can store it, you just do not have a GUI to edit it/give it a value other than from a plugin currently (it will happen in Calibre 0.8 in the coming months).
http://www.w3.org/ns/prov#wasQuotedFrom	mobileread.com