it used to be for a LOOOOONG time and still is in many southern states. my friends and I are some of the few traditionalists, normally I would wear a white shirt with a tie of the school colors but it was in the dirty laundry at the time.
A little bit of a picture explanation: the picture is taken right before a bunch of us are about to "shotgun" cans of beer. this is where u cut open a whole at the bottom of a can (usually with keys) and then open the can while simultaneously turning it rightside up with ur mouth over the open whole causing the beer to rush quickly down your throat.
this guy is a good example