Galactic coordinates referred to the location of star systems on the galactic plane. Every system was located by its XYZ coordinates; X measured the system's "east-west" location, Y measured its "north-south" location, and Z measured its distance above or below the galactic plane. The system was known as the Coruscant coordinates system as it was centered on Coruscant rather than the actual galactic center - Coruscant was dignified with XYZ coordinates of 0,0,0 (Triple Zero in military speak). In the Coruscant system, a parsec was 3.26 light years, with fifteen parsecs corresponding to one unit on the coordinates scale. A negative number for X, Y or Z coordinates indicated that the star system was west of, south of, or below Coruscant's position.