The CSS WG has published an updated Working Draft of Selectors Level 4:
https://www.w3.org/TR/selectors-4/ Selectors are patterns that match against elements in a tree and are used as a core part of CSS and in DOM methods such as .querySelector() This update adds, drops, and renames a number of selectors: * zero-specificity pseudo-class named :where() * :matches() renamed to :is() * :blank defined to select empty user input elements * :empty redefined to ignore whitespace-only text nodes * :drop() dropped due to removal of support in HTML * Added case-sensitive attribute value matching flag In addition, the specificity rules for :is() and :nth-child() were altered to use the most specific selector argument rather than the most specific selector that happened to match. See https://www.w3.org/TR/selectors-4/#specificity-rules and discussion in https://github.com/w3c/csswg-drafts/issues/1027 Changes since the February 2018 WD are all listed at: https://www.w3.org/TR/2018/WD-selectors-4-20181121/#changes One major issue that's open is redefining the way invalid selectors are handled within `:is()` and similar pseudo-classes to ignore unknown selectors rather than invalidating the entire style rule. See https://github.com/w3c/csswg-drafts/issues/3264 Another series of open issues concerns the :visited pseudo-class and how to balance security concerns with usability requirements. See e.g. https://github.com/w3c/csswg-drafts/issues/3012 https://github.com/w3c/csswg-drafts/issues/2263 Please review the draft, and send any comments to the CSSWG mailing list, <www-st...@w3.org>, prefixed with [selectors-4] (as I did on this message) or (preferably) file them in the GitHub repository at https://github.com/w3c/csswg-drafts/issues For the CSS WG, ~fantasai
