APC: Armoured Personnel Carrier. An armoured battle taxi.
ATGM: Anti-tank guided missile. A long-range missile that is guided towards it's target, by an operator.
AFV: Armoured Fighting Vehicle. A generic term typically applied to tanks, but also includes IFVs and some heavy APC designs.
ARV/ARRV: Armoured Recovery Vehicle/Armoured Recovery and Repair Vehicle. A vehicle normally based on a highly modified tank chassis that performs towing, hoisting, and winching operations in the rescue and recovery of combat vehicles.
AVLB: Armoured Vehicle Launched Bridge. A vehicle normally based on a modified tank chassis that transports and emplaces some form of folding assault bridge used to cross ditches, streams, and other battlefield obstacles.
AEV: Armoured Engineering Vehicle. A vehicle normally based on a highly modified tank chassis that performs earth-moving, engineering (welding and cutting), obstacle breaching, and obstacle construction operations on the battlefield. Also known as an AVRE (Armoured Vehicle Royal Engineers) in Commonwealth service.
Coax: A machine gun mounted co-axially that moves with the main gun.
Fully Concealed: No part of the vehicle (or crew) visible (also known as a "hide" position).
Fully Exposed: No part of the vehicle hidden.
GPS: Gunners primary sight.
HEAT: High-explosive anti-tank. A round that uses chemical energy to penetrate armour.
HE-Frag: A Tank round that works like a massive hand grenade; used against infantry and light fortifications.
HESH: High-explosive squash head (also know as High-explosive plastic [HEP]). An HE round that defeats armour by sending a shockwave through the steel, breaking off large pieces of armour material inside. Useful against infantry, bunkers, light armour, and older tanks.
Hull down: Hull is hidden behind a berm.
IFV: Infantry Fighting Vehicle. A vehicle designed to carry an infantry squad on to or through an objective while protecting them from small arms fire, artillery splinter, and NBC contamination and be able to support them with heavy direct fire and provide anti-armour capability.
KE: An armour-piercing round utilizing kinetic energy to penetrate armour. These rounds are further subdivided into full-bore (announced as "AP" in fire commands) and sub-caliber saboted rounds (announced as "Sabot" [say-bo] in fire commands).
LRF: Laser Range Finder.
RPG: Rocket-propelled grenade.
SPAAG: Self-propelled anti-air gun.
Spall: Fragments of steel that is generated by a round penetrating armour.
Tank: Heavily armoured vehicle with high firepower. With a few exceptions, tanks carry no infantry.
Tank-destroyer: Lightly armoured vehicle with a large gun/ATGM.
TIS: Thermal imaging sight.
TOGS: Thermal observation and gunnery sight (Thermal sight on the Challenger, Challenger 2 and late Chieftain series).
TOW: Tube-launched, Optically-tracked, Wire command data link, ATGM.
TTS: Tank thermal sight (on M60A3).
Turret down: Hull and turret is hidden behind a berm, with only commander looking over it.