Ohio Rev. Code § 157.02: Designation of system in land descriptions.

As established for use in the north zone, the Ohio co-ordinate system of 1927 or the Ohio co-ordinate system of 1983 shall be named, and in any land description in which it is used it shall be designated, the Ohio co-ordinate system of 1927, north zone, or the Ohio co-ordinate system of 1983, north zone.

As established for use in the south zone, the Ohio co-ordinate system of 1927 or the Ohio co-ordinate system of 1983 shall be named, and in any land description in which it is used it shall be designated, the Ohio co-ordinate system of 1927, south zone, or the Ohio co-ordinate system of 1983, south zone.