• 211. HOW PRESCRIBED.—The general organization of the antitank warning service and the methods to be employed are prescribed by higher commanders. Usually this will include the method of reporting information, assignment of zones of responsibility for reconnaissance and observation to subordinate elements, and instructions concerning the prompt transmission of information.

• 212. SOURCES OF INFORMATION.—Reconnaissance and observation agencies, particularly aviation, are very important sources of information, but every unit forms part of the warning service. It may be likened to a fire alarm system in a city, with every citizen a potential giver of the alarm.

• 213. FORM OF MESSAGES.—A uniform type of tank warning message is usually prescribed to expedite and simplify transmission of information. Such a message usually includes in a predetermined sequence the number of tanks seen, their type, location, direction of movement, and the time at which they were seen. One type of map only is used in reporting tank warnings.

• 214. WARNING NETS.—a. Arrangement of warning nets varies; the following system appears generally applicable. Certain radio stations in each division and attached units remain constantly open on a prescribed frequency. Only tank warning information is sent over the net. The number of sets in the net is limited; one per battalion or regiment is usual. Any information obtained is flashed over this net. The station at division headquarters is located in a focal center which operates under the division antitank officer. The focal center has a plotting board. It receives all tank flashes, analyzes and interprets the information, and plots hostile movements. The information is conveyed to the designated division staff officer and also flashed over another radio to the tank warning net of corps and army.

b. Within the smaller units tank warnings move through command communication channels but are given priority.

c. A corps and army warning net operates in a similar manner. Stations in the net include each division, corps, and army focal center. Corps and army reconnaissance agencies operate in a separate corps or army net similar to the divisional net. Their information is relayed in a similar manner.

d. Interlocking of nets through the focal centers insures that information will be analyzed before being transmitted, without materially retarding transmission.

• 215. TANK DESTROYER UNITS.—a. Tank destroyer battalions and groups will have radio sets in the warning nets of the units to which allocated.

b. For their security they provide a local warning service of their own. They may be charged with reconnaissance and observation over a prescribed area. The information gained by reconnaissance is flashed to battalion headquarters, where it is transmitted over the radio on the warning net.