I was wondering about session etiquette for the fringe singing sessions, such as that at the Middle Bar. I expect that etiquette may vary by session, but any information would be appreciated on the following:

1) Are there songs that are either officially or unofficially reserved for certain occasions? I mean something along the lines of saving "Leave Her Johnny" or "The Seamen's Hymn" for the final song of a session.

2) Are there songs that are either officially or unofficially reserved for certain people to lead? Here I mean something along the lines of, "Old Fred always leads that one, so the rest of us leave it to him".

3) Are there songs that are just not sung? Here I mean something along the lines of, "Please, lord, not *that* one, we're all sick of *that* one."

4) What about ending a song with a repeated chorus? Is that common? Left to the discretion of whoever is leading the song? Frowned upon?

Thanks in advance for all help!