Signalling Information

Wig-Wag and Semaphore, standard arm and hand signals, ground-air emergency code, panel markers, lights, pyrotechnics and infrared devices. Visual signals are very vulnerable to interception, and the enemy may use similar signals for purposes of deception and confusion. The use of visual signals is restricted during periods of poor visibility, or when line-of-sight locations are not available. Use of visual signals may be prohibited for security reasons.
Illustrations of the various methods of visual communications.

Radio Communication. All commanders down to and including squad leaders are provided with radio communications equipment. Radios are provided primarily for communication within the organization to which assigned and between operating elements of the organization which they are supporting. Before radios can be operated together, they must use the same frequency, modulation, and signal.

Radio Security. Radio is the least secure means of communication. It is always assumed that interception takes place every time a message is transmitted by radio. For this reason, radio communication security is a constant consideration. The enemy obtains information merely by knowing that radios are operating and this may make it necessary to restrict or prohibit their use for periods of time.

Phonetic Alphabet. The phonetic alphabet, shown below, is used in voice communication with radio or wire whenever there is a possibility that the word or letter may be misunderstood during the transmission.