<http://schema.org/query-input>
"required name=search_term_string"^^<http://www.w3.org/2001/XMLSchema#string>
<http://soso.gr/tag/%CE%BD%CF%85%CF%86%CE%B9%CE%BA%CE%B1-%CE%BC%CE%B1%CE%BA%CE%B9%CE%B3%CE%B9%CE%B1%CE%B6/>