ive never seen a school where u can where just a shirt with a marijuana leaf on it, and not get in some kind of trouble(though at my current school if u do something like that they just make u turn it on inside out). how ever u can get away with things like my sublime shirt that has a big mushroom on it or my willie nelson shirt, which just kinda mentions legalizing it.
thats just how my old high school was i'm sure it has become more strict tho gotten cameras, drug dog...and i graduated with 83 kids. there is NO need for that shit in such a small school. although we did have a "bomb threat" once...it was a science project
i wore a ac/dc shirt that said hells bells on the back...i wore it and a teacher is all like YOU CANT WEAR THAT IT HAS A BAD WORD ON THE BACK so im like ok....then a week later i wore it again