Ohio Rev. Code § 5715.12
The county board of revision shall not increase any valuation without giving notice to the person in whose name the property affected thereby is listed and affording him an opportunity to be heard. Such notice shall describe the real property, the tax value of which is to be acted upon, by the description thereof as carried on the tax list of the current year, and shall state the name in which it is listed; such notice shall be served by delivering a copy thereof to the person interested, by leaving a copy at the usual place of residence or business of such person, or by sending the same by registered letter mailed to the address of such person. If no such place of residence or business is found in the county, then such copies shall be delivered or mailed to the agent in charge of such property. If no such agent is found in the county, such notice shall be served by an advertisement thereof inserted once in a newspaper of general circulation in the county in which the property is situated. Notices to the respective persons interested in different properties may be united in one advertisement under the same general heading. Notices served in accordance with this section shall be sufficient.
R.C. §5715.12