The Marine Corps reserves the wear of Sam Browne belts to Officers at parade, ceremonies, honor guards, and reviews when the wear of swords is prescribed; they may also be worn at other times or occasions if the commander deems them appropriate.
Officers wear Sam Browne belts with the Blue Dress “A/B,” Blue-White Dress “A/B,” and Service “A” uniforms over Service and Dress coats, with the bottom portion of the belt around the natural waist and the shoulder strap over the right shoulder; straps allow the belt to be tightened both horizontally around the waist and diagonally across the chest. Like the leather service belt, a sword frog or carrier is attached to the horizonal belt at a point above the highest portion of the hip bone.
The Sam Browne belt’s eponymous name is taken from its inventor, a British Officer in India who commanded the 2nd Punjab Irregular Cavalry who lost his arm in 1857. Browne came up with the idea of additional strap to hold his standard sword belt more firmly in place and thus stabilize the scabbard when withdrawing a sword single-handed. A brown leather version was adopted by the Marines during World War I, but the color was changed to black to make it more consistent with other leather gear worn by Marines and also by U.S. Navy personnel.