Of course.
target -> square -> mark -> select icon
For ease it is often simpler to have a mark bar however, with macros that set the currently target, so you don't have to click through the menu.
But if you actually are doing things ahead of time, the extra time isn't that big of a deal.
Yeah I come across PS3 tanks who mark just fine all the time.
But that said, the PS3 interface doesn't always do a good job at explaining where things are. If you know how to examine/follow/friend/tell another player, you should have seen Mark in the same menu, but I have come across a few players who had never pulled that menu up.
