If after an initial order is entered under s. 767.41 the parties agree to a modification in an order of physical placement or legal custody and file a stipulation with the court that specifies the agreed upon modification, including a modification to physical placement or legal custody upon the occurrence of a specified future event, as defined in s. 767.34(3) (a), that is reasonably certain to occur within 2 years of the date of the stipulation, the court shall incorporate the terms of the stipulation into a revised order of physical placement or legal custody unless the court finds that the modification is not in the best interest of the child. The court may not incorporate the terms of a stipulation that is based on an anticipated behavior modification of a party, including for the completion of any of the following:
Wis. Stat. ยง 767.461
2005 Wis. Act 443 contains explanatory notes.