{if}{else}depending on browser agent
 

Because of Firefox's terrible handling of stylesheets I want to create browser specific tags inside .tpl files.

I didn't find it in the forum, maybe someone can give me a clue

You are kidding right? Firefox is beautiful with stylesheets, it is IE that sucks. In any event, have a look at rectangle_bottom.tpl and button.tpl and you'll get an idea of browser if statements.