The Infantry Drill Regulations state that “the authorized message book should be used and the form therein adhered to.” This book, issued by the Signal Corps, contains fifty message blanks with fifty duplicating sheets, so that fifty messages may be sent and a copy of each retained. The front of the blank appears as on next page. The back of the blank is divided into squares. By means of a ratio between the size of these squares and certain scales for maps, a fairly accurate sketch is possible. _Caution._ Remember that a message may not always go direct from sender to receiver, but may be relayed by several methods of communications—buzzer, helio, or flag. Think how errors may creep in at each change of method, and guard against them by making your message one of telegraphic brevity and unmistakable clearness. +------------------------+----+--------+-----+---------+-----+-------+ | | No.| Sent by| Time| Rec’d by| Time| Check | | =U. S. ARMY FIELD | | | | | | | | MESSAGE.= | | | | | | | | | (These spaces for Signal Operators only.) | +------------------------+-------------------------------------------+ | Communicated by | (Name of sending detachment.) | | Buzzer, Phone, | | | Telegraph, Wireless, | | | Lantern, Helio, Flag, | _From_................................... | | Cyclist, Foot | (Location of sending detachment) | | Messenger, Mounted | | | Messenger, Motor Car, | _At_..................................... | | Flying Machine. | | | | | | Underscore means used. | _Date_........... _Hour_........ _No_.... | +------------------------+ | | _To_.............................................................. | | .................................................................. | | .................................................................. | | .................................................................. | | .................................................................. | | .................................................................. | | _Received_........................................................ | +--------------------------------------------------------------------+