HTML and CSS Reference
Classic CSS implementation that introduced text, list, box, margin, border, color,
and background properties. Initially defined in 1996, most every feature of CSS1
is supported in Web browsers, but small quirks do exist around some lesser-used
features like white-space , letter-spacing , display , and others. Some
problems with CSS1 support are more significant in older, pre-Internet Explorer 7
Specification that is primarily known for positioning and media, particularly print
style sheet features. Many aspects of CSS2, such as aural style sheets, were never
widely implemented and were removed in a later iteration of the CSS specification.
A revision of the CSS2 specification that makes some corrections and is normalized
to more clearly represent what most browser vendors have implemented. Note that
many CSS2 features removed from this specification are found in CSS3 modules.
This is currently the recommended CSS specification for study and use.
Modularized specification of CSS. Various modules extend and improve aspects
of previous CSS versions; for example, the CSS3 Color module addresses color
correction, transparency, and more, while the CSS3 Fonts module addresses
features to add effects to fonts, adjust their display, and even download custom
fonts. Some modules are all new, like the Transitions and Animations modules,
and others are quite old looking with activity levels suggesting they are abandoned
or near abandon. Whatever the situation, when it comes to CSS3, readers are
encouraged to check the CSS3 Web site and test support carefully.
T ABLE 4-1 Description of Common CSS Versions
Some older proprietary CSS
features found in Internet
Explorer are not prefixed in
This applies to all Gecko
browsers such as Firefox.
Opera also supports the
-xv- prefix for experimental
voice support for aural style
sheet properties like -xv-
This applies to all WebKit
engine-based browsers such
as Apple's Safari and Google
T ABLE 4-2 CSS Extension Prefixes