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.