Weapon-Mounted Light
A flashlight mounted to a firearm to identify targets in low light.
Also: WML
A WML lets the shooter identify targets in darkness without occupying a hand on a separate flashlight. It is not a substitute for a handheld light — searching with a WML means muzzling whatever you’re looking at, which violates rule two. Most defensive trainers teach a handheld light first; the WML is for confirmed-threat work.