[csswg-drafts] [selectors] is #42 a valid ID selector?

dstockwell has just created a new issue for 
https://github.com/w3c/csswg-drafts:

== [selectors] is #42 a valid ID selector? ==
https://drafts.csswg.org/selectors/#id-selectors says:

> An ID selector consists of a “number sign” (U+0023, #) immediately 
followed by the ID value, which **must be a CSS identifier**.

But in [the grammar](https://drafts.csswg.org/selectors/#grammar) 
`<id-selector>` is defined as `<hash-token>` which would appear to 
allow a sequence beginning with numbers.

Please view or discuss this issue at 
https://github.com/w3c/csswg-drafts/issues/202 using your GitHub 
account