# Builtin Extends Only

This gist simply lists all elements that can't be extended on "_the platform_" if not through the Custom Elements builtin extends feature.

This list does not focus on the "*why would you?*" rather on the "*why can't you?*" (on Safari) question out there, using the **Permitted Parent** section out of [MDN Element Reference](https://developer.mozilla.org/en-US/docs/Web/HTML/Element).

  * [html](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/html)
  * [base](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/base)
  * [head](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/head)
  * [link](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/link)
  * [meta](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/meta)
  * [style](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/style) - any parent but no way to have it without disrupting the layout
  * [title](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/title)
  * [body](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/body)
  * [main](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/main) - has to be hierarchly correct
  * [dd](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/dd)
  * [dt](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/dt)
  * [br](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/br) - any parent but no way to have it without disrupting the layout
  * [hr](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/hr) - any parent but no way to have it without disrupting the layout
  * [figcaption](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/figcaption)
  * [li](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/li)
  * [rp](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/rp)
  * [rt](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/rt)
  * [area](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/area)
  * [track](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/track)
  * [source](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/source)
  * [script](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/script) - any parent but no way to have it without disrupting the layout
  * [caption](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/caption)
  * [col](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/col)
  * [colgroup](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/colgroup)
  * [tbody](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/tbody)
  * [td](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/td)
  * [tfoot](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/tfoot)
  * [th](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/th)
  * [thead](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/thead)
  * [tr](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/tr)
  * [legend](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/legend)
  * [optgroup](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/optgroup)
  * [option](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/option)
  * [summary](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/summary)