(1) Any person who has filed a complaint with the department or commission or any person on whose behalf a complaint has been filed may make a request in writing that the complaint be withdrawn. If the withdrawal is based on a private settlement, a copy of the settlement agreement must accompany the request.

(2) Upon receipt of a written request for withdrawal of the complaint, the department shall dismiss the complaint either entirely or insofar as it alleges a particular cause of action in favor of the party seeking the withdrawal or seeks an individual remedy for such party.

(3) The department may reserve any part of the complaint which alleges a cause of action in favor of any other person or group or may redesignate the complaint as a commission complaint with respect to any allegation or remedy which is not specific to the withdrawing party alone. Redesignation does not constitute the filing of a new complaint and relates back to the date the original complaint was filed.