3-AC
From SCJU Wiki
3-AC or the 3 Alpha Code is traditionally used by the Terran Aerth Imperium to denote its Viceroyalties, Provinces (Duchies) and Cities.
First introduced under Emperor Arcturus Salvonus Marnx IX, this system became the prevalent system for identification in official documents within the Empire.
This system was introduced to the SCJU by Viceroyalty of Dominea to simplify the SCJU's identification.