I remember when my band directors took me to my first show at Lake Highlands HS in Texas. He took us all aside before going in and said:
"Now this isn't a concert, but it isn't a social club either. Cheer, clap, ooh, and ahh...but don't just sit there and chat, that tends to tick people off. Also, some of these fans are pretty hard, so don't bash any particular corps too much. You never know who's mom, dad, or worse, alumni, is sitting near by. Some may not care that you're in high school. Say the wrong thing and I wouldn't be surprised if you got popped in the mouth, or at least you would've in my day. We all clear? Good."