Wis. Stat. § 701.1310: Formalities.

An exercise of the decanting power must be made in a record signed by an authorized fiduciary. The signed record must, directly or by reference to the notice required by s. 701.1307, identify the first trust and the 2nd trust or trusts and state the property of the first trust being distributed to each 2nd trust and the property, if any, that remains in the first trust.