<http://schema.org/query-input>
"required name=search_term_string"^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.healthmatterslondon.co.uk/?page=shop.product_details&category_id=42&flypage=flypage.tpl&product_id=212&option=com_virtuemart&Itemid=144&vmcchk=1&Itemid=144>