Although DA 670-1 lists only Infantry (light blue) and Marksmanship (blue with red and white serrated markings) shoulder cords, local U.S. Army Commanders have the authority to prescribe the wear of branch-colored shoulder cords, such as these crimson-and-yellow shoulder cords for Ordnance personnel. Crimson has been associated with the Ordnance since 1851, except for a nearly two-decade hiccup beginning in 1902 in which the branch colors were black and scarlet. In 1921, the Army replaced those colors with the primary and secondary colors of crimson and yellow.
Though similar to aiguillettes and fourragères, shoulder cords are worn purely for ceremonial decoration and are not associated with an assignment (aiguillettes are worn by aides) or military award (fourragères reflect unit honors bestowed by a foreign nation).