3 ms·

Or they could have just used arbitrary elements, like <myelement>. Folks forget that this is valid HTML, and it’s just treated as a div.

• recursive 6y ago
  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.