Able= The code name or "phonetic" for the letter A when talking on the telephone or on the radio.
A.R.= Air Burst.
A.C.P.O= Assistant Command Post Officer.
A.G.R.A.= Army Group Royal Artillery.
Aim off= The amount which it is necessary to lay the gun ahead of the target to allow for the travel of the target.
Aim off speed= The speed at which the aircraft is crossing the line of sight in the direction of aim off.
Angle of sight= The angle which the line of sight makes with the horizontal plane.
Angle of departure= The angle which the line of departure makes with the horizontal plane. It differs from Q.E. by the amount of jump and droop.
Approach angle= The angle made by the line of sight with the line of flight of the target.
Azimuth= in A.A. gunnery this is assumed to be the horizontal plane containing the observer.
Air OP= Air Observation Post- a light aircraft piloyed by an artillery observer.
A.P.= Armour Piercing (shell).
APCBC= Armour Piercing Capped Ballastic Cap, a type of anti tank projectiel.
A/S= Angle of Sight-The angle between the line gun-target and the horzontal.
Auster= A type of light aircraft used by Air OP Squadrons.
Area to be blinded= Th enemy locality from which observation over our own troops is to be rendered impossible.
Barrage= A stationary or moving belt of fire providing a protective screen behind which the attackers .
Bamboo= Shells falling on own troops.
Burnt= The moment when the propellant charge is completely consumed.
B.C.= Battery Commander, rank of Major.
B.M.R.A.= Brigade Major Royal Artillery.
B.P.= Bearing Picket.
B.Q.M.S.= Battery Quartermaster Sergeant.
B.S.M.= Battery Sergeant Major.
BT= The imaginary line joining battery to target.
CB= Counter Battery or Counter Bombardment.
CCRA= Commander Corps Royal Artillery.
C.P.O.= Command Post Officer.
C.P.O.A= Command Post Officer Assistant.
C.R.A.= Commander Royal Artillery.
C.R.U.= Canadian Reinforcement Unit.
CCS= Casualty Clearing Station.
Calibration= The comparison of the actual preformance of a gun, instrument, etc, with the standard performance.
Concentrations= Periodic burst of fire on selected hostile areas or batteries.
Corrected, or map, data= The line, angle of sight, and range obtainted from the uncorrected date by subtracting, the correction of the moment and adjusting the range for flase sight, where necessary.
Correction of the moment= The allowance, for range and for line, required to take account of abnormal conditions prevailing at the moment.
Crest angle= The minimum sate angle of departure to clear a crest.
D.F.Task= Defensive Fire Task.
Diver= V1 Missile.
D.R.= Despatch Rider.
Drift= The lateral displacement of the projectile, due to its rotation from the vertical plane containing the line of departure,
Droop= The vertical angle between the axis of the bore at the breech and the axis of the bore at the muzzle.
Echolon= A group in the chain if Supply or Administration.
F.A.T.= Field Artillery Tractor.
F.D.L.= Forward Defended Localities.
F.O.O.= Forward Observation Officer.
F.O.U.= Forward Observer unit.
F.S.= Feet per second.
Final line= The line on which the barrage is completed.
Fixation= The survey process whereby the co-ordinates of a specified point are determined.
G.A.P.= Gun Aiming Point.
G.P.O= Gun Position Officer.
G.P.O.A.= Gun Position Officer Assistant.
Grid bearing= The clockwise angle from grid North to the line whose bearing is to be specified.
Grid convergence= The angle between grid North and true North.
Gun bearing= The bearing on which the gun must be laid in order that the trajectory will pass through the future position. It differs from the future bearing by the lateral wind and drift deflections applied.
H.A.A.= Heavy Anti Aircraft.
H.B.= Hostile Battery.
H.E.= High Explosive.
H.Hour= Zero Hour.
Intermediate lines= The lines on which a barrage changes its direction.
L.A.A.= Light Anti Aircraft.
L.A.D.= Light Aid Detachment of R.E.M.E attached to a Regiment.
L.M.G.= Light Machine Gun.
Lanes= The sections of the barrage within which the fire of an artillery unit or sub-unit moves forward.
Lines= The sucessive lines on which the barrage moves forward.
Line of sight= The straight line from the observer to the target.
Me= Messcherschmitt, German Aircraft.
Mike Target= Regimental Target.
MO= Medical Officer.
M.P.B= Mean point of burst.
M.P.I= Mean Point of Impact.
M.V.= Muzzle Velocity.
Murder= Same name for Stonk, but for a concentration of fire at one point.
Non rigidity correction= The correction to range required to allow for the effect of uphill or downhill shooting
O.C.T.U.= Officer Cadet Training Unit
O.P= Observation Post
O.P.A.= Observation Post Assistant
O.T.= The imaginary line Observation Post Target.
Opening line= The line of the barrage nearest to the starting line.
Pause lines= The lines on which fire is directed to cover our own troops halted on an objective.
Pepperpot= A concentration fired by A.A or anti tank guns, Mortar, MGs etc, in a ground role to strenghten the fire plan for an attack.
Pheasant= Security name for a 17 pounder Anti Tank Gun.
Pivot Gun= The gun on the right flank of the troop position. Guns in action will be numbered 1 to 4 from right to left, the pivot gun being No.1.
Point of origin= The mean position of the smoke producing containers from shells fired by one gun firing at a constant line and range
R.O= Reference object
R.S.O= Regimental Survey Officer
Remaining velocity= The velocity of the projectile at any point of the trajectory.
Robert= Security name for a 6 pounder Anti Tank Gun
Rough grid= A system of unit or sub-unit grids of all of which are known to be sufficiently nearly in.
S.L.T.R.= Swing left, traverse right
S.R.T.L.= Swing right, traverse left
S.T.= Surface Target
Sitrep= Situation Report
Staggered Position= A Troop position in which the guns are sited at irregualr intervals both latterally and in depth.
Starting line= The line from which the foremost attacking troops advance at zero hour.
Stonk= A linear concentration.
Survey= The process of determining and recording the relative positions of points on the surface of the earth.
Target box= A regular area drawn, for simplicity, surrounding an irregularly shaped area which is to be engaged with chemical shell.
Theatre grid= The grid system in terms of which the coordinates of the basic trigonometrical points are given by the survey directorate.
Tester= A smoke round fired in advance, in order to determine whether the points of origin have been established in the correct place
Troop picket= The illuminated mark off which the guns of a troop are laid by night.
U Target= Division Target
Uncorrected, or gun ,data= The line, angle of sight, and range at which the gun hit the target.
V Target= Corps Target
Vertex= The highest point of the trajectory.
William Target= Target to be engaged by all available guns of a Army
Window= a gap in a smoke screen
Yoke Target= A.G.R.A. Target
Zeroing= Adjusting gun sights from fall of shot
Zero Hour= The hour at wich attacking troops cross a starting line
Zero Line= An arbitrary reference line which is established as a basis from which all switches are measured.
Zone of attack= The are formed by the target box together with a frame 100 or 200 yards wide surrounding it.