<http://schema.org/description>
"Facebook has confirmed that some users are experiencing issues with its Groups feature today, after many users complained that their accounts were automatically resubscribing to Groups ..."^^<http://www.w3.org/2001/XMLSchema#string>
<http://thenextweb.com/facebook/2012/11/28/suddenly-getting-notifications-from-old-facebook-groups-its-a-glitch-and-the-company-is-investigating/>