Wisconsin Statutes Employment Relations (Ch. 111) § 111.322. Discriminatory actions prohibited

(1) To refuse to hire, employ, admit or license any individual, to bar or terminate from employment or labor organization membership any individual, or to discriminate against any individual in promotion, compensation or in terms, conditions or privileges of employment or labor organization membership because of any basis enumerated in s. 111.321.

(2) To print or circulate or cause to be printed or circulated any statement, advertisement or publication, or to use any form of application for employment or to make any inquiry in connection with prospective employment, which implies or expresses any limitation, specification or discrimination with respect to an individual or any intent to make such limitation, specification or discrimination because of any basis enumerated in s. 111.321.

(2m) To discharge or otherwise discriminate against any individual because of any of the following:

(3) To discharge or otherwise discriminate against any individual because he or she has opposed any discriminatory practice under this subchapter or because he or she has made a complaint, testified or assisted in any proceeding under this subchapter.