Rule 17. The commissioner of revenue, after completion of the hearing, shall review the record, briefs, and such other matters as may have been submitted and by written order affirm, reverse, or modify the action of the city, and shall further serve upon the appellant or his duly authorized representative and the duly authorized official of the city by registered or certified mail with the return receipt demanded, a copy of his order and opinion.
Mich. Admin. Code R. 205.917