<http://schema.org/category>
"web ready license"^^<http://www.w3.org/2001/XMLSchema#string>
<https://marketplace.500px.com/photos/6721350/like-a-statue-%25EC%25A1%25B0%25EA%25B0%2581%25EC%2583%2581%25EC%25B2%2598%25EB%259F%25BC-by-baro-kim>