Sometimes I'm at a dog show early enough that we get "caught" by the anthem. It's really annoying because you want to be respectful, but there really isn't a point where everyone is gathered and there is an opening ceremony or something. Everyone is all spread out, racing dogs to all the different rings and getting set up. So it kind of becomes this awkward moment were everyone sort of half freezes when they hear the loudspeaker go off and tries to figure out where the flag is so you can face in that direction.
I tend to go with the crowd. If they are doing it right, I'll do it. If they aren't paying attention, then I don't much bother anyway. I figure it's better than trying to lead through example and getting run over by some handler's assistant rushing to ringside and being annoyed because people are rude.
