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[1] Petty Officer First Class Affiliation UNSC Navy Higher Rank Chief Petty Officer Lower Rank Petty Officer Second Class Known Petty Officer First Classs Frederic-104 Healy Jai-006
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Petty Officer First Class is the sixth enlisted rank of the UNSC Navy and is a non-commissioned officer. It is equal in rank to Staff Sergeant in the UNSC Marine Corps.

In informal settings, Petty Officers First Class are typically called "Petty Officer".

Sources

1. ↑ This is the insignia for a U.S. Naval Petty Officer First Class in the Hospitalman rating. However, in Halo 3 the insignia for Master Chief Petty Officer is shown to be the same as for the U.S. It is inferred that this applies to all UNSC Navy Enlisted rank insignes.