The first update in 30 years to the US Army "Visual Signals" (PDF) manual has just been issued. It's filled with black-and-white sketches on how in-the-field soldiers can signal events to one another—from warning about a "nuclear hazard present" to "take a knee." The military notes that, for the most part, the signals apply to "both men and women."

Efficient combat operations depend on clear, accurate, and secure communication among ground units, Army aviation, and supporting Air Force elements. Control and coordination are achieved by the most rapid means of communication available between Soldiers and units. When electrical and/or digital means of communication are inadequate, or not available, a station-to-station system of visual communication is an alternate means for transmitting orders, information, or requests for aid or support.

The Army notes that the signals are not a panacea for when electronic communications run dry. For starters, they are "vulnerable to enemy interception," and their effectiveness is "significantly reduced during periods of poor visibility, and when terrain restricts observation."















Listing image by Visual Signals/US Army