<http://schema.org/interactionType>
"http://schema.org/CommentAction"^^<http://www.w3.org/2001/XMLSchema#string>
<http://thenextweb.com/apps/2012/03/01/read-later-is-a-great-mac-client-for-instapaper-and-read-it-later-and-now-its-free/>