Cover (military)

In military combat cover can either refer to a barrier (usually already at the scene of battle) which can be used for protection or concealment, or it can refer to the shielding or protection of persons on the battlefield (usually on the move) by those with either superior training/equipment, or in a more secure position.

In some military services (especially in the US), a hat is sometimes referred to unofficially as a cover, as in "Soldier, remove your cover!" or "You're not in uniform without your cover."