When I had just started officiating, I was watching two guys work the varsity game. The trail made a few calls in the lead's area during the second quarter. I had already asked if I could join their pregame, halftime and postgame sessions to listen, ask questions and learn.
At half, the lead walked into the locker room they were using, grabbed a dry board marker and drew a quick diagram with the coverage areas then sat down without saying a word about it to his partner. During the second half, his partner stayed out of his area.