Just trying to look at the updates to https://dom.spec.whatwg.org/#valid-element-local-name and I feel like there's a discrepancy...

The regexp (/^(?:[A-Za-z][^\0\t\n\f\r\u0020/>]*|[:_\u0080-\u{10FFFF}][A-Za-z0-9-.:_\u0080-\u{10FFFF}]*)$/u) validates that a-\x01 returns true but as best as I can see the regexp does not follow the spec prose. Specifically the first match group of /^[A-Za-z][^\0\t\n\f\r\u0020/>]*$/ says "must start with a letter, then should be any character except these code points" but the prose says something quite different.

Am I missing something obvious?