U.S. NAVY / USCG COMMANDER AND USMC LIEUTENANT COLONEL COAT RANK DEVICES
Officers in the O-5 pay grade are designated as Commanders in the Navy and Coast Guard, while they are known as Lieutenant Colonels in the Marine Corps (as well as in the Army and Air Force). A silver oak leaf has been used as the rank insignia for Commanders in the Navy since 1862, the same year that Lieutenant Commanders began wearing gold oak leaves as their insignia of grade.
The rank of Lieutenant Colonel has existed in the Marine Corps since its inception, when Congress appointed two of them to serve in two battalions of Marines that were to be commanded by a single Colonel, the highest rank in the Corps at that time.
In the Navy, Commanders wear the metal insignia of grade on the All-Weather Coat, blue jackets, and black jack¬ets. The device is placed on the shoulder straps of these outerwear garments centered between the front and rear of the strap, 3/4-inch from the shoulder armhole seam and with the stem of the oak leaf facing away from the collar. Commanders in the USCG follow identical guidelines when wearing the silver oak leaf with the Trench Coat and Windbreaker.
USMC regulations for the wear of the silver oak leaf on a variety of coats and jacket is essentially the same as those used by the Navy and Coast Guard, with only one difference: “Field grade oak leaves will be worn with the stem toward the armhole seam.”