Chief of Staff (Secretary)

The Chief of Staff for the Secretary of Starfleet is the gatekeeper to the highest person within Starfleet. Oftentimes, the "Coz" is himself a retired Starfleet officer, maybe a long-time friend and confidant of the Secretary, but may also be a career bureaucrat. He is the direct-report for the three other chiefs, as well as the two Starfleet officers that fall outside the uniformed chain of command (the Judge Advocate General and the Inspector General).

The Chief of Staff is not a PC.