The annual Simulated Emergency Test (SET) is a training exercise involving the Amateur Radio Emergency Service (ARES) and the National Traffic System (NTS), a message-handling service of amateur radio. The American Radio Relay League is a prime mover in this event, which is organized somewhat like a contest. Its primary purposes are to evaluate strengths and weaknesses in emergency preparedness and communications, and to demonstrate amateur radio to the public.

External reference

http://www.arrl.org/FandES/field/pscm/sec1-ch2.html