Ohio Rev. Code Ann. § 1329.63

The secretary of state shall establish for convenience of administration a classification of goods or services that is in conformity with the classification established by the commissioner of patents and trademarks under 15 U.S.C. 1112 but that does not limit or extend the applicant's or registrant's rights. A single application for registration of a trademark or service mark may include any or all goods and services comprised in a single class on or in connection with which the trademark or service mark is actually being used, but a single application shall not include goods or services that fall within different classes on or in connection with which the trademark or service mark is being used.