Not a Doom III fan myself,but for those interested:
Under the crazy presumption that a roll of duct tape has to exist somewhere on the Mars facility, the Duct Tape mod sticks flashlights to your machinegun and shotgun. In order to preserve the atmosphere, these new lights are much narrower (and a little brighter) than the standard flashlight, and are only available on the basic weapons. The pistol is not equipped with a flashlight, so as not to spoil the early sections of the game.
Or are mods as these considered as cheating?
Don't start flaming me if it is,please (Or if it's old news).