[mukunda_johnson]

I'm surprised this is well defined behavior.

[creatonez]

It certainly is now (HTML5 retroactively standardized a lot of quirks), but it wasn't always well-defined: https://scrappy-do.blogspot.com/2004/08/little-rant-about-mi...

[zahlman]

I already saw the Stack Overflow reference cited in the article (https://stackoverflow.com/questions/8318911) many years ago, so I wasn't surprised.

But I guess I can still be disappointed. Postel's Law has its limits.

[Ygg2]

Postel or Hyrum?