The United States Navy’s rank insignia for its Chief Warrant Officers is unique in that different systems are used for collar insignia as opposed to the insignia displayed on sleeves and shoulder boards of dress uniforms. In fact, “confusing” might be a better word to describe the design the Navy has wound up with following the elimination of the lowest CWO grade (W-1) in 1975 and the creation of a new grade (CWO-5) in 2002.
A system of gold/silver bars on a blue background is used for CWO-2 to CWO-4, but because the Navy did not change the insignia system after discontinuing the W-1 grade, it almost seems haphazard. Until that time, the four grades were rendered as one gold bar (W-1), two gold bars (CWO-2), one silver bar (CWO-3), and two silver bars (CWO-4), which made sense because silver indicates a higher rank than gold. For the addition of the CWO-5 insignia, the Navy wisely used a single, thin horizontal line in place of vertical bars to represent the grade—but it flipped the colors so the background is silver and the line indicating grade is blue.
For sleeve and shoulder board rank insignia, on the other hand, silver was eliminated completely and, for some reason, the Navy decided to indicate higher grades by removing blue bars or hashmarks from the gold lacing stripe. Under this system, a CW-2 insignia has three blue bars, while the CW-4 rank has just one. This “addition by subtraction” system is found nowhere else in U.S. Armed Forces rank insignia system, which presumably makes it unforgettable (or not).