<http://schema.org/query-input>
"required name=search_term_string"^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.codingforums.com/php/288285-comparing-multi-array-keys-other-multi-array-keys.html?s=1483d1b329b9a24b760b5da1d7af880e>