Each of these groups is shown in the feature films to have various types of uniforms but never have been shown wearing any type of identifying insignia. The uniforms appear to range from Soldiers and Technicians, to Sergeants and Naval NCOs, as well as Warrant Officers and Command Sergeants. Imperial enlisted personnel have never been shown to have any type of insignia, but do have various types of uniforms which could indicate seniority among the enlisted rank structure. Over the years, however, the Expanded Universe has established a system of ranks and insignia which matches closely to the characters and the ranks and authority which they most likely held. With such generic terms, the Star Wars films give little hint to a system of ranks and insignia. Grand Moff Tarkin was referred to as ”Governor”.

It should be noted that ”commander” is an acceptable form of address for captains, majors, colonels, or anyone of any rank who commands a military unit. In the Galactic Civil War, most Imperial officers were verbally addressed as ”Commander” with the exception of Admirals, such as Admiral Kendal Ozzel and Piett who were addressed as ”Admiral”. By the next few years, the rank squares had become a much simpler collection of red and blue squares with the code cylinders still in use.

In 0 BBY, Imperial officers of the Galactic Empire wore insignia consisting of a confusing collection of multi-colored rank squares on the left breast of the officer’s uniform with a combination of several metal cylinders to either side of the rank badge.

Star wars imperial navy ISB