Rear admiral

Rear Admiral was a flag officer rank used by naval organizations, traditionally between the grades of Commodore and Vice Admiral. This rank was used by the Federation Starfleet (as well as its predecessor the Earth Starfleet). Some systems instead used two tiers of Rear Admiral rank, "Rear Admiral Upper Half" and "Rear Admiral Lower Half." Officers of the lower half were equal in grade to Commodores.

Rear Admiral Ranks
List of Rear Admirals