Sorry, I have no wish to be argumentative, but I don't think that "Their Party, Their Rules" works at all.

No blacks? No Irish? No Indians? No Wops? No Spicks? No Chinks? No Kikes? No women?

That's got to be OK, because "Their Party, Their Rules".

Sorry, but I don't think it is a sliding scale - it is an absolute.

I could agree that banner/colour parties should meet a dress code, but to stop clan followers marching who don't meet the code IS discrimination.