The proceedings of the township board shall be published at least once each month. The publication of a synopsis of such proceedings, prepared by the township clerk and approved by the supervisor, showing the substance of each separate proceeding of the said board shall be a sufficient compliance with the requirements of this section. The said board shall determine the method of publication of all notices, ordinances, and proceedings for which a mode of publication is not prescribed by this act or ordinance. The said board shall determine that such publication shall be made in a newspaper, as defined by state law, which is published and circulated in the township, if there be one so published and circulated, or in the event that there be no such newspaper, then in one published in the county in which the township is located, or that such publication shall be made by posting in the office of the clerk and in 5 other public places in the township. In case publication is made by posting, a notice of such posting, setting forth by a descriptive phrase the purpose or nature of the notice, ordinance or proceeding posted, and location of the places where posted, shall be published at least once in a newspaper, as above required, within 7 days after such posting was done.