Ohio Rev. Code § 4907.37: Unlawful preference.

No common carrier subject to Chapters 4901., 4903., 4905., 4907., and 4909. of the Revised Code shall make or give undue or unreasonable preference or advantage to a particular person, company, firm, corporation, or locality, or to any particular description of traffic, or subject any particular person, company, firm, corporation, or locality, or any particular description of traffic, to any undue or unreasonable prejudice or disadvantage in any respect.