Usually they have membership system. Organizer will plan the party, 5 star hotel suite is the norm or AirBNB in some guarded high keras area (also the reason why so many resident against AirBNB). Joining fee have to be paid in advance, siap with STD report etc within a week from event.

Afaik they all wear masquerade mask during party for various reasons. U feel more confident when u dont fully expose your face, all become more wild more daring. Booze supplied depending on majority and strictly no drugs.