ORIGINAL PRE WORLD WAR II UNITED STATES NAVY & MARINE CORPS COMMANDER RANK OAK-LEAF INSIGNIA, LARGE 1 INCH x 15/16 INCHES, SCREW-BACK. In the United States, commander is a military rank that is also sometimes used as a military billet title-the designation of someone who manages living quarters or a base-depending on the branch of service. Please let me know if there’s anything else I can do for you!