Wisconsin Statutes Property (Ch. 700 to 710) § 700.05. Classification of remainders

(1) Indefeasibly vested, if the interest is created in favor of one or more ascertained persons in being and is certain to become a present interest at some time in the future;

(2) Vested subject to open, if the interest is created in favor of a class of persons, one or more of whom are ascertained and in being, and if the interest is certain to become a present interest at some time in the future, but the share of the ascertained remaindermen is subject to diminution by reason of other persons becoming entitled to share as members of the class;

(3) Vested subject to complete defeasance, if the interest is created in favor of one or more ascertained persons in being and would become a present interest on the expiration of the preceding interests but may end or may be completely defeated as provided by the transferor at, before or after the expiration of the preceding interests;

(4) Subject to a condition precedent, if the interest is created in favor of one or more unborn or unascertained persons or in favor of one or more presently ascertainable persons upon the occurrence of an uncertain event.