M— Minus: meaning fire observed at least 50 yards short of target. T— Right: meaning fire observed to right of target. C— Centre: meaning direction of fire correct. U— Unobserved: meaning no observation obtained. Q— Query: meaning fire observed, but its position uncertain. R— Range: meaning range correct. The signaller at the observation post should give the “call up” to show that the observers are ready. “P” and “M” may be repeated for multiples of 50 yards; thus, “PP” would mean, “Fire observed at least 100 yards beyond target.” Signals should be repeated from the gun position if this can be done without disclosing the position to the enemy. On all occasions when guns are firing, the following signals should be used in controlling fire:— Signal for “Action.”—Both arms fully extended, raised from the sides to a position in line with the shoulders and lowered again. This motion to be repeated until it is seen that the signal is being complied with. Note.—A machine gun is said to be “In Action” when it is mounted, loaded and laid, but not necessarily firing. Signal for “Out of Action.” Arm swung in a circular motion in front of the body. By No. 2. Hand up—Gun ready to open fire. By Controlling Officer. Hand u— Preparatory to opening fire. Hand dropped—Open fire. Elbow close to the side, forearm waved horizontally—Cease fire. GENERAL MACHINE GUN COURSE. Extracts from War Office Letter No. 9/General Number/4976 (M.T. 2), dated 14th May, 1915. 1. PERSONNEL. The following table shows the establishment of the Service Machine Gun section to be maintained in the following units:—New Armies, Reserve Units, Territorial Force Units, Colonial Contingents.