In Simon Collison\'s new old Responsive Web Design, in the CSS, there are several declarations like this:
@-moz-document url-prefix() {
.f
From https://developer.mozilla.org/en/CSS/@-moz-document
@-moz-document url(http://www.w3.org/),
url-prefix(http://www.w3.org/Style/),
domain(mozilla.org)
{
/* CSS rules here apply to:
+ The page "http://www.w3.org/".
+ Any page whose URL begins with "http://www.w3.org/Style/"
+ Any page whose URL's host is "mozilla.org" or ends with
".mozilla.org"
*/
/* make the above-mentioned pages really ugly */
body { color: purple; background: yellow; }
}