Praise, in my experience with singers nights in folk clubs and sessions, the correct ettiquite is for the performers to learn the way a venue works as much of it is based on learning the feel for a place. I would hate to see such venues producing a written set of rules.

I have been MC in a folk club on a few occasions and I would try to spot newcomers and ask them if they wanted to sing but I them to listen and try to get a feel for the club and ask any questions they feel necessary. The sort of questions I had were usually "Do you alow contemporary or is this club strictly traditional"? or "is it OK to sing a Beatles song"?

Jon