<http://schema.org/topics>
"branding,Business,Business Lists,contributor,Facebook,flickr,How To,Lists,Marketing,Social Media,Social Network Lists,social networking,Twitter,web,web 2.0,YouTube"^^<http://www.w3.org/2001/XMLSchema#string>
<http://mashable.com/2009/02/27/social-media-for-business-2/>