Input Tags In Forms Not Valid XHTML →
https://marco.org/2007/04/29/input-tags-in-forms-not-valid-xhtml
I can’t believe this… <form><input/></form> is invalid in XHTML Strict. All <input> elements must be inside other block-level elements (even though <form> is a block-level element) under <form>. Who thought that was a good idea? Not a web developer, I bet…