<http://schema.org/isFamilyFriendly>
"true"^^<http://www.w3.org/2001/XMLSchema#boolean>
<https://marketplace.500px.com/photos/22403865/%25D0%2595%25D0%25BB%25D1%258C%25D0%25BD%25D0%25B8%25D0%25BA-by-denis-taraskin>