<http://schema.org/query-input>
"required name=search_term"^^<http://www.w3.org/2001/XMLSchema#string>
<https://www.zen-cart.com/showthread.php?192566-Can-I-force-html-with-every-email&s=b7bd2841f4c9f0af3ca4bf0589637445&p=1105207>