Wis. Stat. § 842.05: Pleadings.

(1) The complaint shall describe the lands to be partitioned and the interests of all parties as far as the same are known to the plaintiff. If a lienholder is made a defendant, the lienholder’s lien shall be described.

(2) If the complaint does not demand partition of all the lands owned by the parties any of them may have the complaint amended so as to affect all the lands so owned.