We tend to think of protocol as a diplomatic thing-- should Americans curtsey to the Queen, for instance, but these sorts of generally accepted rules also guide everyday situations. Do you call your doctor by her first name? How about your child's second grade teacher? Who gets the last seat in a crowded room, or on the train? We all know these things because of accepted protocols, and we're all offended when they are violated.
Figure skating sessions do have protocols as well, and in fact very specific ones for very specific situations, having less to do with diplomacy and more with safety. So here's a few.
Right of way
Right of way on free skate sessions is very specific, and universal. Lower level skaters have the right of way. Therefore, no stink eye allowed by the Novice level skater toward the pokey, tentative Freestyle 2 skater. Someone running a program with music and the pinney or belt on has the right of way. Someone in a lesson has the right of way. On Pairs and Dance sessions, a team executing a lift has the right of way.
Other rink behaviors
Don't stand in the lutz corner. Teach from the boards (i.e., coaches should not stand in the middle of the ice while teaching-- this is as bad as anyone standing in the middle of the ice. If you must be out on the ice while teaching, you should be moving.) Pay before you get on the ice, don't make the monitor chase you down. Wear a belt or pinny if you are running your music. Don't wear the belt or pinny until you are running your music. Nothing more confusing than three people wearing markers because "I was next!"
There are lots of do's and don'ts that I'm not sure reach the level of protocol but are more rules or accepted practices that may vary from rink to rink. Many rinks don't allow colored drinks, like coffee or soda, on the ice. While sitting on the boards is universally frowned on, some rinks tolerate it and some don't. There will be rink-specific protocols: which ice door to use to enter/exit, length (or indeed existence) of a warm-up period on each session, acceptable clothing. Not everyone will do these things the same way.
Don't spread your crap all over the place, and throw away your trash. This does not apply only to skating.
Since public sessions are full of people who can't be expected to know skating protocols, the guards enforce what amount less to protocol and more to actual rules. They will be posted and generally include no holding hands with more than 1 person, no carrying children on the ice, the center coned area is for lessons and figure skating practice, no hotdogging (too fast for conditions), everyone skate in the same direction, no sitting on the boards, etc.
There are no universal protocols for program play. Every rink will have set up its own system. The main accepted protocol for music is that if your music is playing you have the right of way. But there are some generally accepted polite practices, for instance, even on a session where no one else is playing their music, for pity's sake don't play it 10 times in a row.
Hokay, here we go. Do not walk around to the coaches' area by the boards. I really can't think of anything that coaches hate more than mothers who do this. No standing in the ice door. Now, I'm going to stop here, because other typical annoying parental behavior does not actually violate what I would call "protocols" which have developed in skating around safety and flow issues. So things like "don't scream at the coach, the skating director, or your child in the lobby" is not so much a protocol as just evidence of bad behavior.
Protocols and rules are there to make skating safe, productive and fun. They can be summed up succinctly: don't be a jerk.
What are some protocols or rules that I've missed, or that are specific to your rink?