Should <button> contain nested DOM element or not?

Question

I did not realize is it bad or not, according to the W3C rules about HTML semantic writing - how we should write the button element with descended elements?

In way, like this one:

<button>
 <div>
   <span>'hi'</span>
 </div>
</button>

or only this:

<button>'hi'</button>

Answer 1

I tested your code in W3C Validator & the error shown is

Element div not allowed as child of element button in this context. (Suppressing further errors from this subtree.)