These hacks don't validate, but are 100% safe according to CSS parsing rules. Check the specification and compare results with Opera and Safari first! Firefox 2.0 or olderIf you need to make pre-Acid2 Firefox behave, you can safely use this: #hackme, x:-moz-any-link {styles for Firefox 2.0 here} #hackme, x:-moz-any-link, x:default {restore styles for Firefox 3.0 and newer}This hack will apply rule