(17. Answer: short)
18. Security, distance, enemy situation, and message length are considera-
tions as to whether __________________ communications will "get the message
(18. Answer: sound)
19. Visual signaling is another means of communication available to all
units. An advantage of _______________________ communication is that it is readily
(19. Answer: visual, available)
20. Visual signaling employs flags, lights, pyrotechnics, panels, arm-and-
hand signals, aircraft maneuvers, end any other devices or techniques pre-
arranged to be sighted or seen by those for whom messages are intended. Such
means are suitable for transmitting prearranged messages rapidly over short
distances, and for recognition and identification of friendly forces. Visual
signals are easily misunderstood and are very vulnerable to interception.
In addition, the enemy may use similar signals for purposes of deception and
confusion. Their use is restricted during poor visibility or when line-of-
sight locations are not available, and may be prohibited for security reasons.
Visual communications are particularly useful when radio silence must be
imposed, in reconnaissance operations, and in situations requiring special
control. Visual signals are easily _______________________ and vulnerable to
_________________ , _________________ ,and _________________ .