Somebody on another moped forum had this definition. Must have a stock, or modified stock production moped frame, must have a production based engine, brand of engine and frame must be the same, cases must be stock or modified stock, no manual transmission, must have functional pedals, (after all, it's not a moped without pedals), must have headlight and tail light, although these do not need to be stock, you can use clip on bicycle lights. Can have any type of wheels or tires, exhaust, seat, bars, does not need fenders or mirrors, can be based on either a top tank or stepthrough. This seems like a pretty good set of rules to me. Peace. Jerry.