Obsolete since Gecko 6.0 (Firefox 6.0 / Thunderbird 6.0 / SeaMonkey 2.3)
This feature is obsolete. Although it may still work in some browsers, its use is discouraged since it could be removed at any time. Try to avoid using it.
A media group defined by the CSS standards.
Note: This media group was never fully implemented in Gecko and was removed in Gecko 6.0.