Which title is not a Navy E-rank?

The title "Corporal" is not a Navy E-rank because it is a rank used in other branches of the military, specifically the Marine Corps and the Army, to denote proficiency and leadership at a junior level. In the Navy, the enlisted ranks are structured differently, with titles such as Chief Petty Officer, Petty Officer First Class, and Senior Chief Petty Officer being part of the Navy's established hierarchy.

The Navy typically uses the "Petty Officer" classification, which includes several pay grades from Third Class up to Chief and Senior Chief. Each of these ranks has distinct responsibilities and expectations within the naval framework. The title of Corporal does not fit within the Navy's ranking system, making it clear that it is the outlier in this grouping.