<http://schema.org/query-input>
"required name=search_term_string"^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.getdpi.com/forum/gear-fs-or-wtb/54831-canon-fd-stuff-f-1-50-1-4-35-2-24-2-8-17-3-5-a.html>