Black Mug 15oz - Army - 1st Bn 3rd Infantry Regiment - Washington DC - The Old Guard w Inf BranchBlack ceramic 15 oz (0. 44 l) Rounded corners C handle Microwave safe Dishwasher safe The 3rd United States Infantry Regiment is a regiment of the United States Army. It currently has three active battalions and is readily identified by its nickname, The Old Guard, as well as Escort to the President. The regimental motto is Noli Me Tangere (from Latin: "Touch Me Not"). A regiment is a major unit of the Military District of Washington (MDW).