I think the t-shirt rule is stupid. whenever I see a kid wearing a band shirt at that band's concert I just think he or she is excited and enjoying him/herself. I like seeing the concert shirts from previous tours, too.
at the Dallas show there was some kid wearing a Bellyflop Communists shirt. I thought it was neat.
whoever wrote those rules had to be either joking or the most anal, elitist person to ever attend a concert.
I will enjoy my concert experience however I please and if other people don't like it they can kiss my asssssssss.