Well, a simple start would be for the event organiser/host to simply and not punatively publish the list of actuall attendee's. It would not be belittling to the people who didn't show, rather it would give kudo's to those who did.
IMO, as far as tentatives go, a lot of players sign up as tentatives simply to have a spot if and when the numbers get large enough for thier liking, and to wait and see if thier friends sign up. I have actually had people admit this to me. This is particularly rude to a person organizing a game with a player cap. I'm sorry but if you don't know until last minute... don't post until last minute. A few players always post that they are out at the last minute. So, the opposite effect is true. Personally, at furure games I host, I won't be adding tentatives to the list. You're in or you're not.
My 2 pence!
Douglas Alexander Maxwell (Known pedophile).