The game keeps track of ff kills, and if you die to it you have the choice of typing "np", or "forgive" in any chat to stop it counting against the killer.
there's plenty of friendly fire, just everyone seems fairly reasonable about it. especially if they're up sneaking around the enemy area, from 200yds, any bloke sneaking from barrel to tree etc is fair game. or a particularly foolish move is for any allied player to pick up a panzershreck, which goes on your back and is generally big and obnoxious looking and makes a nice target.
If you dont at least try to recognize your targets you'll end up with alot of grief points and get booted from the server, which does happen of course, though not as much as you might expect from other shooters you may have played. Which is not to say the servers are lax on teamkillers, the game just isnt mainstream enough to have massive ammounts of asshats.
You actually have to want to play it to find it, Red Orchestra wasnt that big of a seller. (despite its terrific attention to detail and physics and aiming engine) Generally people dont care what happened to the soviets circa 1944. (and this is a mod off of that game)
Sometimes you have to suffer for the sake of your art. But if you're lucky you can have someone else suffer for your entertainment.