Ohio Rev. Code § 4907.38: Rebate or concessions prohibited.

No person, firm, or corporation, shall knowingly accept or receive a rebate, concession, or discrimination in respect to transportation of property wholly within this state or for service in connection therewith, whereby such property, by false billing, false classification, false weighing, or other device, is transported at a less rate than that named in the published tariffs in force, or whereby any service or advantage is received other than that specified in such tariffs.