Ohio Rev. Code Ann. § 5715.29

The tax commissioner shall prescribe such general and uniform rules and issue such orders and instructions, not inconsistent with law, as he deems necessary, as to the exercise of the powers and the discharge of the duties of all officers which relate to the assessment of property and the levy and collection of taxes. The commissioner shall cause the rules prescribed by him to be observed, the orders and instructions issued by him to be obeyed, and the forms prescribed by him to be observed and used.