<http://schema.org/description>
"Back in September, Google announced the culling of a number of its lesser-used services. Among them was Sidewiki, the company's attempt at Web annotation. Today users of the service ..."^^<http://www.w3.org/2001/XMLSchema#string>
<http://thenextweb.com/google/2011/11/02/googles-web-annotation-experiment-sidewiki-to-close-on-5-december/>