Not an exhaustive list, but a few observations from my 23 years of visiting messes and knowing what can really T off the natives - most are about basic courtesy!
- Don't wear / carry outdoor coats, hats or briefcases in public areas (ante room, dining room, bar, etc)
- Be considerate of fellow diners during meals - if at breakfast, recognise those who 'just wish to be alone' and don't try to force conversation
- If in a hushed anteroom, don't sit in a large gaggle, discussing the days camp events - if you need a 'work' type meeting, public areas are not an appropriate place (unless empty of livers in)
- Learn what the dress code is, when it applies and the meaning of any 'traffic light signals'
- Don't expect the bar to stay open until you decide to order the last round - if it is a very quiet night, the steward may wish to shut the bar early
- Don't hog the remote / channel hop in the TV Room if others are there
- If someone's waiting for the snooker table and you're just having a knock about / just having a very slow game, at least offer the table to those waiting
- Try to learn who the Stn Cdr / PMC are and what they look like - that way, you can recognise who they are when they appear in the bar in mufty!
- During Sqn beer calls, try to identify if anyone is hosting and ask permission before joining in - offer thanks at the end
- During happy hour, don't just try to buy rounds at half price and expect to get everyone else to pay when it's full price!!
- Try to learn something about the station, its roles and key issues, so that you can understand / contribute to bar conversations
- Learn humility / honesty!
As I say, most are just basic courtesies (but not all visiting staff seem to be aware of these).