I love all the ritualized behaviour, secret meanings and unexpected taboos - standing up when someone of higher status stands, elaborate rules for serving and eating, tapping the table to thank the server, never refuse a toast from a superior, stuff like that.
Whether it’s about meals or anything else, I’d love to hear about any uncommon politeness standard or similar social behaviour that goes on in your location, culture or restaurant!
It’s essentially a shibboleth, a way to confirm that you’re in the “inner circle”. Tribalism is still one of the strongest force in social science it seems, even if we start with lots of identical people they’ll try to differentiate and discriminate between each other.