thumb|upright|British smoke grenade with various markings, including "Grenade Hand Smoke Screening Training L83A1" designation

The L number ("L" standing for Land Service) or weapon identity number system is a numerical designation system used for the type classification of British Army weapons and related stores. The L number in isolation is not a unique identifier; rather, it is used in conjunction with a description, e.g. "Rifle, 7.62mm, L1A1" or "L1A1 7.62mm Rifle". Stores coming into Army service began receiving Land Service designations in 1954, replacing the old number-and-mark system of designations.

The L number system does not have universal application. Some items have been referred to in official documentation by their manufacturer's designations instead of L numbers. Likewise, legacy items that were given designations under the earlier number-and-mark system have continued to be referred to by those designations until their replacement by newer stores. A number of guided weapons in British service such as the K170A1/A2 NLAW HEAT Guided Missile and the K130 High Velocity Missile use a "K" designation rather than a Land Service one.

Equivalent designation systems were devised for the Royal Navy ("N", standing for Naval Service) and the Royal Air Force ("A", standing for Air Service), Land Service designations have also been used where no Army equivalent exists, as in the case of the Royal Navy's L44A1 Machine Gun. The FV (fighting vehicle) number series is similar in purpose but not in formatting. Similar designation systems are used by various other militaries; for example, Canada uses "C" (standing for Canadian), Australia uses "F" (standing for Forces), and several nations such as Denmark, South Africa, and the United States of America use or used "M" (standing for Model or its non-English equivalent).

Firearms

  • L1
  • L1A1 7.62mm Self Loading Rifle (SLR) (Also referred to as the L1A1 7.62mm Rifle)
  • L1A1 .50 inch Anti-Aircraft Machine Gun Mounting (For use with the L1A1 MG)
  • L1A1/A2/A3 66mm HEAT Rocket and Launcher (Also referred to as the L1 66mm Section Anti-Tank Rocket)
  • L1A1 66mm Sub-Calibre 21mm Adaptor (Training adaptor for L1 66mm HEAT Rocket)
  • L1A1 Straight Sighting Telescope (Modified No. 32 Mk 3 Sighting Telescope as used with the L42A1 rifle)
  • L1A1 Illuminating Hand Thrown Flare
  • L1A1 Necklace Demolition Charge
  • L1A1/A2 12 kg Conical User Filled Demolition Charge
  • L1A1 Small Arms Bore Cleaning Brush
  • L1A1/A2/A3 Safety Fuze
  • L1A1/A2 9mm Magazine (Magazine for use with the L2 submachine gun; L1A1 magazines were manufactured by Sterling while L1A2 magazines were variously manufactured by ROF Fazakerley, Royal Laboratories Woolwich, Rolls Razor, and Mettoy)
  • L1A1/A2/A3 Image Intensified Weapon Sight (Also referred to as the L1 Individual Weapon Sight (IWS), L1 Image Intensified Weaponsight, or L1 Individual Weaponsight)
  • L1A1 Image Intensified Weapon Sight Mount (Mount for L1 IWS to be used with the L7 GPMG)
  • L1A1 Small Arms Cleaning Rod
  • L1A1/A2 Grenade Discharger (Used for firing the L11 anti-riot grenade)
  • L1A1 Armoured Vehicle Periscopic Sight
  • L1A1 Telescope (Leupold spotting scope with Cullmann tripod)
  • L1A1 Nerve Agent Pre-Treament Tablet Set
  • L1 120mm Battalion Anti-Tank Gun
  • L2
  • L2A1/A2 High Explosive Hand Grenade (Also referred to as the L2A1/A2 Anti-Personnel Hand Grenade, which is particularly apparent on the grenade markings)
  • L2A1 Anti-Structures Munition
  • L2A1 7.62mm Rifle
  • L2A1/A2/A3 9mm Submachine Gun
  • L2A1/A2 Trilux Infantry Sight Unit (Abbreviated to SUIT after "Sight Unit, Infantry, Trilux")
  • L2A1 Irritant One Shot Hand-Held Discharger
  • L2A1 .30 in. Machine Gun Tripod Mounting (Tripod mounting for L3 Machine Gun series)
  • L2A1 Light Non-Metallic Anti-Tank Mine
  • L2A1/A2 Electric Demolition Detonator
  • L2A1 Image Intensified Weapon Sight Mount (Mount for L1 IWS to be used with the L14 anti-tank gun)
  • L2A1 Image Intensified Armoured Vehicle Periscopic Sight
  • L2A1 51mm Mortar (L10A1 mortar without ancillary items)
  • L2A1 12.7mm Drill Purpose Machine Gun (Drill purpose version of the Browning M2)
  • L3
  • L3A1-A4 .30 in Machine Gun
  • L3A1 Non-Metallic Anti-Tank Mine
  • L3A1 Anti-Tank Mine Clearing Equipment
  • L3A1/A2/A3 Handheld Electronic D.C. Exploder
  • L3A1/A2/A3 Practice Hand Grenade (Training version of the L2 HE/APERS Hand Grenade)
  • L3A1-A5 Flash Initiator
  • L3A1 Small Arms Collimator (For use with the iron sights and CWS on the SA80 series)
  • L4A1/A2 Drill Hand Grenade (Drill version of the L2 HE/APERS Hand Grenade)
  • L4A1 Flash Initiator
  • L4A1 Image Intensified Weapon Sight Mount (Mount for L1 IWS to be used with the L1 SLR)
  • L4A1 Machine Gun Tripod Mounting (Tripod mount for L7)
  • L4A1 Image Intensified Weapon Sight Adaptor (Mount for the L5 and L6 sights; Also referred to as the L4 Image Intensified Weaponsight Adaptor)
  • L4A1 Smoke Generator
  • L4 120mm "MOBAT" Battalion Anti-Tank Gun Equipment
  • L5A1 Combination Demolition Firing Device
  • L5A1 Detonating Cord
  • L6A1 Blank Firing Attachment
  • L6 120mm "WOMBAT"