The CSS Working Group invites implementations of the Selectors Level 3 Candidate Recommendation. Selectors are patterns that match against elements in a tree, and as such form one of several technologies that can be used to select nodes in an XML document. Selectors have been optimized for use with HTML and XML, and are designed to be usable in performance-critical code. This document describes the selectors that already exist in CSS1 [CSS1] and CSS2 [CSS21], and further introduces new selectors for CSS3 and other languages that may need them.
CSS (Cascading Style Sheets) is a language for describing the rendering of HTML and XML documents on screen, on paper, in speech, etc. CSS uses Selectors for binding style properties to elements in the document.