@kalgynirae I concede. I just checked the W3c spec. [The button element](http://www.w3.org/html/wg/drafts/html/master/forms.html#the-button-element) is valid [in any phrasing context](http://www.w3.org/html/wg/drafts/html/master/dom.html#phrasing-content-1). What I'm confused about now is why so many people do CSS-buttons with `<a>` tags.