I had same problem, no help and I couldn't find it anywhere - So now I'll save you the trouble mate:
Code:
if(classid == 0) {
GameTextForPlayer(playerid,"~n~~n~~n~~n~~b~POLICE~n~~w~Cop",6000,5);
} else if(classid == 1) {
GameTextForPlayer(playerid,"~n~~n~~n~~n~~b~BALLAS~n~~w~Gangster",6000,5);
This shows the classes Team (POLICE or BALLAS in this case) and the specific class name underneath their team name, in the bottom of the screen(just above the [<< >> Spawn] panel)
Stays for 6 seconds. Edit 6000 to how many seconds you want(in miliseconds)
Classids: The first class you added (the one on top of the AddPlayerClass list) is classid 0. The next one is classid 1, then 2, 3, 4 and so on. Add this code under 'public OnPlayerRequestClass(playerid, classid)'.
There you go mate