<http://schema.org/description>
"The importance of Facebook's Open Graph announcement cannot be overstated.\r\n\r\nBy providing a 'Like' button that developers can add to any website, for any content or subject, Facebook ..."^^<http://www.w3.org/2001/XMLSchema#string>
<http://thenextweb.com/socialmedia/2010/04/21/ignore-facebook-open-graph-peril-web-30/>