In the United States Navy, officers have various ranks. Equivalency between services is by pay grade. United States Navy commissioned officer ranks have two distinct sets of rank insignia: on dress uniform a series of stripes similar to Commonwealth naval ranks are worn, while on service khaki, working uniforms (Navy Working Uniform [NWU], and coveralls), and special uniform situations (combat utilities, flight suits, and USMC uniforms when worn by Navy officers assigned or attached to USMC units), the rank insignia are similar (there are subtle differences in the size, shape, and design of naval services insignia) to the equivalent rank in the US Army or US Air Force.