The W3C CSS Working Group has published two new CSS3 modules as working drafts. CSS3 Module: Cascading and Inheritance "describes how values are assigned to properties. CSS allows several style sheets to influence the rendering of a document, and the process of combining these style sheets is called 'cascading'. If no value can be found through cascading, a value can be inherited from the parent element or the property's initial value is used." This working draft contains nothing new conceptually, but constitutes a redraft of relevant portions of CSS level 2 as a CSS3 module; "all the properties and features described which also exist in CSS level 2 are intended to be backwards compatible." The working draft for CSS3 Module: Values and Units "describes the various values and units that CSS properties accept. Also, it describes how 'specified values', which is what a style sheet contains, are processed into 'computed values' and 'actual values'. There are five main types of values in CSS: (1) keywords -- e.g., "pitch-range: inherit"; (2) numbers -- e.g., "orphans: 3"; (3) numbers with unit identifiers -- e.g., "border-width: 0.2em"; (4) strings -- e.g., "content: 'Figure: '"; (5) functions -- e.g., "background: url(http://www.w3.org/image)"; (6) special cases -- e.g., "color: #F00" and "font-size: Helvetica". Most properties accepts values from several of the above types. Some properties accept space- or comma-separated lists of values. Each CSS property has a formal definition of what types of values it accepts which can be found in the description of the property..."
Bibliographic information for CSS3 Module: Cascading and Inheritance. W3C Working Draft, 13-July-2001. Edited by Håkon Wium Lie (Opera Software). Version URL: http://www.w3.org/TR/2001/WD-css3-cascade-20010713. Latest version URL: http://www.w3.org/TR/css3-cascade.
Bibliographic information for CSS3 Module: Values and Units. W3C Working Draft, 13-July-2001. Edited by Håkon Wium Lie (Opera Software) and Chris Lilley (W3C). Version URL: http://www.w3.org/TR/2001/WD-css3-values-20010713. Latest version URL: http://www.w3.org/TR/css3-values.