<http://schema.org/isFamilyFriendly>
"true"^^<http://www.w3.org/2001/XMLSchema#boolean>
<https://marketplace.500px.com/photos/16469795/%25D0%25A2%25D0%25B0%25D0%25BD%25D1%258E%25D1%2588%25D0%25B0-by-vitaliy-rode>