Mich. Comp. Laws § 125.4203d
An ordinance enacted by a municipality that has a population of greater than 1,000 and less than 2,000 establishing an authority, creating a district, or approving a development plan or tax increment financing plan, or an amendment to an authority, district, or plan, and all actions taken or to be taken under that ordinance, including the issuance of bonds, are ratified and validated notwithstanding that notice for the public hearing on the establishment of the authority, creation of the district, or approval of the development plan or tax increment financing plan, or on the amendment, was not published, posted, or mailed at least 20 days before the hearing, provided that the notice was either published or posted at least 10 days before the hearing or that the authority was established in 1990 by a municipality that filed the ordinance with the secretary of state not later than July 1991. This section applies only to an ordinance or an amendment adopted by a municipality before January 1, 1999 and shall include any bonds or amounts to be used by the authority to pay the principal of and interest on bonds that have been issued or that are to be issued by the authority or the incorporating municipality. An authority for which an ordinance or amendment to the ordinance establishing the authority has been published before February 1, 1991 is considered for purposes of section 203(3) to have promptly filed the ordinance or amendment to the ordinance with the secretary of state if the ordinance or amendment to the ordinance is filed with the secretary of state before December 31, 2002. The validity of the proceedings or findings establishing an authority described in this section, or of the procedure, adequacy of notice, or findings with respect to the approval of a development plan or tax increment financing plan for an authority described in this section is conclusive with respect to the capture of tax increment revenues for a bond issued after June 1, 2002 and before June 1, 2006. As used in this section, "notice was either published or posted" means either publication or posting of the notice occurred at least once.
MCL 125.4203d