FWIW, you can generally figure out what's allowed fairly quickly by checking the content model for a given element[1]. Some browsers might be more or less restr

FWIW, you can generally figure out what's allowed fairly quickly by checking the content model for a given element[1]. Some browsers might be more or less restrictive, but for normal usage this'll be more than enough to avoid unexpected behavior. [1]: https://html.spec.whatwg.org/#the-button-element:concept-element-content-model https://html.spec.whatwg.org/#the-button-element:concept-ele...