Over on Facesuck, @NickPitt has raised a good question about casting: every responsible theatre-style GM now asks “is there anyone you don’t want to roleplay with” (or some equivalent) in their casting quiz. But almost nobody tells the players who is in the game when they’re asking this question. Meaning there’s both a danger of under-sharing - not telling the GM about a problem because you don’t think it’ll pop up - and of over-sharing: giving the GM a complete list and flooding them with irrelevant information.
The obvious solution is to let the players know who is playing. This works for cons, where players are assigned before casting begins, but it obviously doesn’t work for one-offs, which usually use a combined signup/casting quiz. It also doesn’t work so well where there are late signups: people might not inform the GM of a conflict with someone because they weren’t on the player list, then have problems emerge when they sign up late and are cast to interact with them.
In terms of how to do this, remember that posting player lists publicly without consent violates people’s privacy. Use an email, or (if its going to be updated) a link-shared google doc. Telling the players who is going to be in the game isn’t telling them anything that they’re not going to find out anyway, so you’re on solid privacy ground, but you should generally tell people you’re doing it anyway just to be on the safe side. Make sure your casting form includes a privacy statement, and make sure it says something like “your information may be shared with other players for game purposes”.
Any other suggestions?