https://courts.michigan.gov/Courts/MichiganSupremeCourt/rules/Documents/HTML/CRs/Ch%202/Court%20Rules%20Book%20Ch%202-Responsive%20HTML5/Court_Rules_Book_Ch_2/Court_Rules_Chapter_2/Court_Rules_Chapter_2.htm

This rule applies to civil and domestic relations cases referred to mediation under Court Rules 2.410 and 3.216. Under this rule, all mediation communications are confidential, not subject to discovery and inadmissible as evidence. Mediation communications include written and oral communications made during a mediation session or in the course of preparing for or planning mediation. The rule lists specific exceptions to confidentiality, such as when all parties agree otherwise in writing. When allowed, the rule also specifies the permitted scope of disclosure.