From SAM USA parent organisation rule book.
The competition flying of free flight and R/C model aircraft of vintage design is intended to be casual, enjoyable and interesting for both competitor and spectator alike. It is neither desired to advance the state-of-the-art of aeromodeling, per se, other than to increase participation in the sport generally, nor to reprove again that which is already recorded in aeromodeling history books. The intent of these rules is to categorize the basic types of vintage models and establish an equitable and simple framework of regulations for competition purposes. Therefore, model designs that revolutionized free flight competition and necessitated the formation of two basic classifications, "ANTIQUE" and "OLD TIMER" are expected to compete in the Old Timer Events.