Colonel (United States) Colonel (United States) In the United States Army, Marine Corps, and Air Force, colonel () is the most senior field grade military officer rank, immediately above the rank of lieutenant colonel and immediately below the rank of brigadier general. It is equivalent to the naval rank of captain in the other uniformed services. The pay grade for colonel is O-6. The insignia of the rank of colonel, as seen on the right, is worn on the officer's left side (a mirror-image version is worn on the right side, such that the eagle always faces forward to the wearer's front; the
Australian Army officer rank insignia below from highest to lowest: The rank of second lieutenant has been phased out of the Australian Army, with officer recruits now graduating from the Royal Military College, Duntroon with the rank of lieutenant. SCDT and OCDT are equivalent rank titles. The rank of Officer Cadet is given to those who are studying at the Australian Defence Force Academy. Their rank is then changed to Staff Cadet upon entry to the Royal Military College, Duntroon (RMC-D) where they become a part of the Corps of Staff Cadets. Officer cadets wear a 10mm wide white stripe, on a DPCU slide or