Petty Officer Second Class

Petty Officer Second Class is the fifth enlisted rank (E-5) of the UNSC Navy and is a non-commissioned officer. It is equal in rank to Sergeant in the UNSC Marine Corps and UNSC Army, or Staff Sergeant in the UNSC Air Force. Directly above is Petty Officer First Class, and Petty Officer Third Class is the rank directly below. This rank is given to all SPARTAN-IIs upon graduation.Halo: The Fall of Reach, page 99 This is most likely due to combat situations in which a Marine NCO has been neutralized, allowing a SPARTAN-II to take command of a squad.
In informal settings, Petty Officers Second Class are typically called "Petty Officer." 
==Known Personnel==
*Shiela Polaski
*James-005
*Li-008
*Joshua-029
*Vinh-030
*Samuel-034
*Isaac-039
*William-043
*Nicole-458
*Anton-044
*Linda-058
*Malcolm-059
*Kelly-087
*Grace-093
*Jerome-092
*Douglas-042
*Alice-130
*Jai-006
*Cassandra-075
*Lucy-B091
*Min-B174
*Tom-B292
*Adam-B004
*Jane-A203
*Robert-A057
*Shane-A112
*Sheila-065
==Sources==
Category:UNSC Enlisted Ranks
Category:UNSC Navy Ranks