Commanding Officer (CO)
The CO is the overall commander of the ship or facility, and is generally referred to as Captain regardless of actual rank. He/she generally controls operations during Alpha shift, and gives commands to all crew. Starbase CO's are responsible for controlling arrivals/departures and movements of all ships. The CO is also responsible for the safety of everyone under his/her command, and is also held accountable for crew actions. The CO must also ensure that all Starfleet and Federation rules and regulations are followed. During Emergencies the CO is called as Duty Officer on the Bridge or in Main OPS at bases. The CO reports to Starfleet Command.
Executive Officer (XO)
The XO is second in command, also referred to as the First Officer. If the CO is absent, he/she can take over his/her duties. He/she can give orders to anyone except the CO, and usually leads any away teams or special missions. All department heads report to the XO, who also deals with organizational schedules aboard station. During Emergencies the XO is called to the Bridge or Main OPS.
Second Officer (SO or 2O)
Usually the most Senior Department Head takes the role of Second Officer, and can assume the role of XO or CO if needed. The Second Officer typically takes Bridge or Main OPS Command during Third Shift. Reports to the XO.
The Yeoman is an enlisted administration position. They complete file work, general secretarial duties and transport sensitive messages on occasion. Reports to the officer they are assigned (CO, XO or other).
Command Master Chief (CMC)
The Command Master Chief, also called the Chief of the Boat and Quatermaster on some vessels; is the senior Enlisted Officer of the vessel/base. He/she is the liaison between the Enlisted Corps and Fleet Officers. The CMC sets the agenda and protocols in training of crew and assists with matters regarding the good order and discipline of the crew as well as procedures and practices which affect the mission, readiness, welfare and morale of the enlisted in the command. He/she maintains all official logs, the official 'clock' for the base/vessel, makes duty assignments for the bridge stations, and may assume any OPS, Bridge or Operations role as required. The CMC is typically the most senior enlisted person, however, the commanding officer is neither required to select the most senior in grade or in time aboard, nor is he or she required to select the highest-ranking crewman. Likewise, the CMC is not necessarily replaced should a more senior NCO reports aboard. The CMC may temporarily act as CO or XO if so ordered, and reports to the XO.