<http://schema.org/description>
"Facebook has shared some insights into just how content appears in your News Feed and what's important to you. At its monthly whiteboarding session, the social network talked about ..."^^<http://www.w3.org/2001/XMLSchema#string>
<http://thenextweb.com/facebook/2012/11/16/facebook-shares-insights-of-page-feed/>