I have heard a few people mention it in passing as they reply on a thread or something of the sort, but no one has said what band etiquette IS, or what it SHOULD BE, so I'm about to jot down a few little things that I think it should be.
1. Have fun in the stands (Minus being rude/lewd and beatting up drunken fans or hecklers.), but be stone-cold professionals marching in/out the stadium and on the sidelines before the show. These are the times when people REALLY see the bands. Normal people are not really watching the bands while they are in the stands because they are stationary, so they don't expect to see anything.
2. Play at appropriate times for the flow of the game, because we actually there, believe it or not, to support the football teams.
3. One thing that I know we always did every game in high school, and I think would be a good thing for the colleges to do, is send over the DM's and section leaders to the away team side for a meet and greet with the opposing bands DM's and section leaders.
Anyone else have anything to add along the lines of general courtesies and do/do nots?