Mich. Comp. Laws § 440.1308: Performance or promise of performance; effect of reservation of rights; applicability of subsection (1) to accord and satisfaction.

Sec. 1308.

(1) A party that with explicit reservation of rights performs or promises performance or assents to performance in a manner demanded or offered by the other party does not prejudice the rights reserved by that performance, promise, or assent. Words such as "without prejudice", "under protest", or the like are sufficient.

(2) Subsection (1) does not apply to an accord and satisfaction.