Mich. Comp. Laws § 289.4119

Sec. 4119. (1) Except as otherwise provided in subsection (2), a person licensed as a food establishment under this chapter shall keep a copy of the current license or temporary license furnished by the department posted and exposed in a conspicuous place for public inspection. A conspicuous place is the principal place where food business is transacted. (2) In the case of vending machines, the name and address and telephone number of the current vending machine location operator shall be conspicuously displayed on each vending machine.