Dress codes are okay. Wearing nose rings is silly, IMO, but that's preference. Having nose rings qualify for expulsion also seems silly, but you *do* have to draw the line somewhere. (and stand by it) Having rules you don't actually enforce is just bad practice.

In the end, I think I have to side with the school. What if a little cult crops up that requires members to do something ridiculous in public? That's obviously a problem for public schools. Just wait for the Fellowship of the Clothing-Free to crop up... Yikes.