Uniform of the Union Army letters US. Officers, NCOs and cavalry troopers were equipped with a sword belt with a rectangular buckle with eagle motif. Rank was displayed on epaulettes (dress occasions) or shoulder straps(field duties): no insignia for a second lieutenant, one gold bar for a first lieutenant, two gold bars for a captain, a gold oak leaf for a major, a silver oak leaf for a lieutenant colonel, a silver eagle for a colonel and one, two or three silver stars for a general, depending on his seniority. The color of the shoulder strap fields – with trims in gold braid – were
Shoulder mark and affixed to the underside of the board. This effectively hides all the means of attachments, leaving a firm, finished surface. This particular style is what U.S. Air Force personnel call a "shoulder board". The shoulder sleeve is called an epaulette, and the two are never confused. On the United States Army Blue Service Uniform, officers wear embroidered rank insignia "shoulder straps" mounted lengthwise on the outside shoulder seams. These are 1⅝ inches wide by 4 inches/3½ inches (large size/small size) long, and are sewn, snapped, or clipped onto each shoulder. The Boy Scouts of America uses colored shoulder loops