<http://schema.org/about>
"Come one, come all. Next Saturday is the annual California Coastal Beach Cleanup and you're invited! People all across California will be participating in restoring beaches all at the same time, next Saturday September 20,"^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.treehugger.com/culture/california-coastal-cleanup-day-september-20.html>