Do you want to know how the CSS WG works? Fantasai has written about:csswg, An Inside View of the CSS Working Group at W3C.
The CSS Working Group has published an updated Working Draft of CSS Syntax. This module describes, in general terms, the basic structure and syntax of CSS stylesheets.
This is a complete rewrite of the obsolete 2003 draft. It describes CSS tokenization and parsing in imperative recursive decent style, and exhaustively covers error handling. Additionally, the An+B syntax used in :nth-child() and related Selectors is not described in terms of the same tokenizer as the rest of CSS.
Changes since CSS 2.1 are listed in the Changes section.
As always, please send feedback to the (archived) public mailing list firstname.lastname@example.org with the spec code (
[css-syntax]) and your comment topic in the subject line. (Alternatively, you can email one of the editors and ask them to forward your comment.)