Can a label only refer to input elements?

Question

W3Schools have this to say about labels:

The tag defines a label for an input element. _{[Emphasis mine]<}

Answer 1

I would say it was not an appropriate use of the markup, because label semantics are that they are specifically for controls.

The LABEL element is used to specify labels for controls that do not have implicit labels,

http://www.w3.org/TR/html401/interact/forms.html#h-17.9.1