UNSC Rankings [Naval and SII-SIIIs]

These ranks are lore accurate and have been confirmed by 343.

NAVCOM Ranks

-Admiralty-
O-10 Fleet Admiral (FADM) [Fleet Commander]
O-9 Admiral (ADM) [HIGHCOM STAFF]
O-8 Vice Admiral (VADM) [Command of Sector Fleet or Academy]
O-7 Rear Admiral (RADM) [Battle Group Commander]

-Officers-
O-6 Captain (CAPT) [Captain of line warship or installation]
O-5 Commander (CDR) [HIGHCOM staff or captain of small warship]
O-4 Lieutenant Commander (LCDR) [First Officer on small warship or command of ship department]
O-3 Lieutenant (LT) [Command of work division or Captain of support ship]
O-2 Lieutenant Junior Grade (LTJG) [Command of staff section]
O-1 Ensign (ENS) [Initial Officer Posting]

-Junior Officers-
WO-2 Chief Warrant Officer (WO-2) [Command advisor or captain of utility ship]
WO-1 Warrant Officer (WO) [Resident technical expert]
OT Cadet (CDT) [No command Authority]

{Although Master Chief Petty Officer is the official rank held by many naval servicemen, they are typically referred to as "Top Chief" by crew out of respect for John-117, more commonly known as "The Master Chief".}
-Enlisted-
E-9 Master Chief Petty Officer (MCPO) [Fleet Administration or HIGHCOM staff]
E-8 Senior Chief Petty Officer (SCPO) [Oversight of ship enlisted personnel]
E-7 Chief Petty Officer (CPO) [Deck Supervisor]
E-6 Petty Officer First Class (PO1) [Work division supervisor]
E-5 Petty Officer Second Class (PO2) [Compartment supervisor]
E-4 Petty Officer Third Class (PO3) [Work party lead]

-Junior Enlisted-
E-3 Crewman (CR) [Work Crew]
E-2 Crewman Apprentice (CA) [Initial fleet assignment]
E-1 Crewman Recruit (CR) [Boot camp and training school)

-Conscripts and Trainees-
E-0 Trainee TRNE
E-0 Conscript CNSPT