<input> within a <form>

I was validating a page today when I got the error:

Error: element “input” not allowed here; possible cause is an inline element containing a block-level element

At first I was confused, but a Google search for that error message quickly pointed me in the right direction. Apparently, <form> must contain a block-level element. And, as <input> is just an inline element, directly enclosing it with a <form> tag wasn’t allowed.

So, I enclosed the tags within <form> by a <div>, and the page now validates as XHTML 1.1. Standards are good :).