CSS hacks are often misunderstood wit IE hacks. Most of the designers look for IE hacks as IE has been a headache for the html coders community. But actually we need hacks for all major browsers and most important of them is Firefox.

Firefox2


html>/**/body .selector,
x:-moz-any-link {
color:red;
}


Firefox3


html>/**/body .selector,
x:-moz-any-link, x:default {
color:red;
}


Firefox4


@-moz-document url-prefix() {
.selector {color:red;
}
}