I’m really glad you asked that particular question faceless internet person. Because I actually do have an opinion on this one.
It’s a simple rule actually – you go to someone else’s event it would be rude to promote your own while you are there. Unless you asked permission.
So that’s the rule – ASK ME before you post something about another group ESPECIALLY another writing oriented group. 9 times out of 10 I’m going to say “yes”. You do it *without* asking first though 9 times out of 10 it’s going to be deleted.