Wis. Stat. § 853.325: Effect of reference to acts or events.

A will may dispose of property by reference to acts or events that have significance apart from their effect on the disposition of property under the will and that do not occur solely for the purpose of determining the disposition of property under the will. Reference to the execution or revocation of another individual’s will fulfills the requirements under this section. This section applies whether the acts or events occur before or after execution of the will or before or after the testator’s death.