<http://schema.org/about>
"Every week, we've been asking you to help vote on new Double Impact challenges so that you can keep earning points and rewards for your favorite charity! But now your vote can also earn you a"^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.treehugger.com/culture/double-impact-challenge-on-healthy-eating-habits.html>