Ahh, possibly I ahve the wrong end fo the stick then. I don't think I know people who have asked that and actually meant that they wanted to know more. I think I would look really confused and say "anything that isn't in the previous list."

Ignore me :) I never make sense anyway.

Fair enough :-)

At least one person did insist rather strongly on knowing more, saying they had had bad experiences before with guests who said "oh, I can eat anything" and it had turned out the meal they cooked was entirely composed of things the guest only just tolerated.

For example, I'd feel somewhat unenthusiastic if someone served me a meal consisting entirely of courgettes, green lentils and white bread; but if any one of those ingredients cropped up in a meal that I otherwise liked, it probably wouldn't affect my enjoyment, so none of them would particularly occur to me as things to warn people to avoid.