<http://schema.org/about>
"Labels on food items are as numerous as the aisles they're sold in, and many proclaim that they're helping you be healthy, helping the planet, or both. The truth is that there are myriad labels out there that"^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.treehugger.com/green-food/7-food-certification-programs-you-need-to-eat-green.html>