I thought I saw players wearing the alternate appearances not to long ago. the german and russian officer costumes and the americans use the tank tops right? So I looked it up to see how to do it and get this: You can change your appearance by changing your "costume" at an armory. But I get no option to do that. I am playing on the official Invasion servers and sometimes unofficial ones and Domination.

I saw something about them only being in deathmatches, is that true?

For now it is true - uniformes are changable only at PVP maps. Whether it will be possible to put on diffrent uniforms or not on other maps and gameplay styles - I do not known.

My WWII mod does allow you to change into a different uniform via a vest - but that only works there because all soldiers wear a modified vest (for gameplay purposes). I suppose you could make a vest that has absolutely no impact on the survivability of the user and change the skin of the soldier that way (and make them respawn with it, of course).

And having it in vanilla would be nice, no doubt.

Fairly easy to mod using the 'vest' system.

The guy with the sweatshirt is supposed to be Rambo, btw.