Emphasis Preaching Journal

Military aircraft and ships must be prepared to operate amid hostile situations. In such an environment it is dramatically important to be able to differentiate between one's allies and one's foes. One way to do so is through the use of passwords and signals known to one's comrades, but not to one's enemies. Passwords and signals have long been the only safe way to effect passage back into friendly positions on the battlefield. In the modern technological age more sophisticated methods have been developed. The IFF (Identification Friend or Foe) signal serves such a purpose.