I have contributed to other people's dinner parties occasionally unsolicited but I (nor anyone I know personally) have never actually thrown a party like that and no one I have invited to my place has ever brought anything (other than perhaps a bottle of wine) so, I have never had that problem, ElainaA. But then I am a 'foodie' and something different and interesting - outside the 'norm' - would probably be a real treat and I would showcase it if I could (without hurting anyone else's feelings, of course). I have never moved in a circle which did the 'potluck supper' kind of thing when it came to entertaining - not sure why not though. That was mostly reserved for things like church suppers and the like in my experience. I have also lived in 'communal' circumstances where people cooked together - but didn't bring in things from outside. However, when I did take anything to a dinner party I never felt they actually had to put It on the table, mind you (and, if unsolicited, it was usually a small dessert type treat - not to overshadow the host/hostess - just to show my appreciation for being invited). They could keep it for later or they could throw it out behind my back and it would not have bothered me somehow. I never asked even for the dish it was contained in/on to be returned - I made sure it was disposable or was purchased as part of the 'gift'.
I would say however, if someone asks people to bring a 'casserole' with recipe for a cookbook, but doesn't say more than that, they may be leaving a lot open to interpretation and may have to put up with 14 dishes full of spaghetti chicken (apparently a southern dish and guftporter is in a southern state so it is probably at least known there) or 4 mac and cheese dishes and 10 tuna casseroles or whatever. And they deserve what they get in that case - although this may be more organized than that and we just don't know it. Maybe they have explained more that gulfporter didn't relate (will ALL recipes brought be included in the cookbook, and if not, will some people feel really left out if theirs isn't? etc.). In the absence of further instruction, I say one should take whatever one interprets to be a 'casserole' and feels like making, all else being equal.
