Ga. Code § 44-4-22
The plane coordinate values for a point on the earth's surface, used to express the geographic position or location of such point in the appropriate zone of the Georgia State Plane Coordinate System, shall consist of two distances expressed in either meters and decimals of a meter or, following conversion as provided in Code Section 44-4-27, in feet and decimals of a foot when using the Georgia State Plane Coordinate System. One of these distances, to be known as the East or x-coordinate shall give the distance east of the Y axis; the other, to be known as the North or y-coordinate shall give the distance north of the X axis. The Y axis of any zone shall be parallel with the central meridian of the zone. The X axis of any zone shall be perpendicular to the central meridian of that zone.
OCGA § 44-4-22