Like most military forces, the NMX uses an IFF system using transponders on their ships.
NMX transponders are connected to the ship's power. If the ship loses power or the transponder is pulled from its housing, the IFF codes are lost from the memory. The transponder can only accept codes. It cannot output them. The IFF codes are only good for 12 hours. Codes are not stored in the ship's computers, but rather encrypted in the minds of the ship's captain and a signal technician.