Commissioned Officers in the O-6 grade are designated Captains in the United States Navy and Coast Guard and as Colonels in the United States Marine Corps, the three branches of the Armed Forces of the United States that require collar grade insignia to be worn certain uniforms. A silver eagle is used as the insignia for this grade in these branches as well as in the Army and Air Force, but the latter two do not employ collar grade insignia.
Worn on both collar points of the shirt worn with the Service Khaki uniform in the Navy, the insignia is positioned so that the eagle’s head is facing to the front, i.e., an inboard direction. Line officers wear the insignia on both collar points; Commanders serving as Staff Officers wear the insignia on the right collar point and a Corps insignia on the left Collar point.
In the Marine Corps, the eagles are also facing inboard when worn on the collars of khaki shirts and on the collars of utility and camouflage maternity coats, but the eagle should be positioned in such a way that when the khaki shirt collar is buttoned, the wings will be perpendicular to the bottom of the shirt collar. On utility coats, the eagles will be worn with the wings perpendicular to the deck. Commanders may prescribe for a black version of the insignia to be worn on certain utility and camouflage uniforms.
This insignia is also used a headgear rank device by all three of these services. On the Garrison Cap, the eagle is worn on the wearer’s right side of the cap with the eagle’s head facing toward the front of the cap. The insignia is positioned so that the eagle is facing to the wearer’s right when worn on the front of a ball cap (U.S. Navy and Coast Guard).