"There are a variety of strategies to allow users to select the appropriate content:
Use content negotiation to serve content per the client request. For example, serve the French version of a document to clients requesting French." 
"CSS2 lets users access alternative representations of content that is specified in attribute values when the following are used together:
Since many mobile browsers don't support CSS1 and CSS2 these attributes aren't really helpful.
"The CSS2 "media types" (used with @media rules) allow authors and users to design style sheets that will cause documents to render more appropriately on certain target devices. These style sheets can tailor content for presentation on braille devices, speech synthesizers, or TTY devices. Using "@media" rules can also reduce download times by allowing user agents to ignore inapplicable rules." 
Copyright © 2001-2003 by Rainer Hillebrand and Thomas Wierlemann