3 ms·

I don't think they forgot, because it was never true. It needs a dash `-` in it. https://html.spec.whatwg.org/#valid-custom-element-name https://html.spec.wha

I don't think they forgot, because it was never true. It needs a dash `-` in it. https://html.spec.whatwg.org/#valid-custom-element-name https://html.spec.whatwg.org/#valid-custom-element-name

folmar 6y ago
It needs them now, but it wasn't always the case. In html5-20121025 User agents must treat elements and attributes that they do not understand as semantically neutral. It was also in the grey area in HTML4.01 spec, note B.1 provides for user agents rendering any unknown elements.
- Conlectus 6y ago
  Semantically neutral yes, but they are not divs -- they're "unknown elements", which have more annoying behavior (similar to pseudoelements from memory)
  - ehnto 6y ago
    I think that's right. They start out life as inline-block elements.