https://html.spec.whatwg.org/multipage/forms.html#the-button-element
https://dom.spec.whatwg.org/#htmlcollection
https://dom.spec.whatwg.org/#interface-document
https://html.spec.whatwg.org/multipage/dom.html#the-document-object
https://html.spec.whatwg.org/multipage/dom.html#htmlelement
https://html.spec.whatwg.org/multipage/forms.html#the-fieldset-element
https://html.spec.whatwg.org/multipage/embedded-content.html#the-iframe-element
https://html.spec.whatwg.org/multipage/forms.html#the-input-element
https://html.spec.whatwg.org/multipage/forms.html#the-label-element
https://html.spec.whatwg.org/multipage/forms.html#the-legend-element
https://html.spec.whatwg.org/multipage/embedded-content.html#htmlmediaelement
https://html.spec.whatwg.org/multipage/embedded-content.html#the-object-element
https://html.spec.whatwg.org/multipage/forms.html#the-option-element
https://html.spec.whatwg.org/multipage/forms.html#htmlselectelement
https://html.spec.whatwg.org/multipage/tables.html#the-table-element
https://html.spec.whatwg.org/multipage/forms.html#the-textarea-element