Ohio Rev. Code Ann. § 5529.08

At any improved roadside rest area along highways of the interstate systems or the primary system, the names of Ohio residents who are listed by the United States department of defense as prisoners of war or missing in action from the Korean conflict or the Vietnam conflict may be memorialized by means of an appropriate marker listing all such persons. The design, size, and specific placement of the markers, in accordance with section 5913.30 of the Revised Code, shall be subject to the approval of the director of transportation.