Wis. Stat. § 62.03: First class cities excepted.

(1) This subchapter, except ss. 62.071, 62.08 (1), 62.09 (1) (e) and (11) (j), (k), and (m), 62.175, 62.23 (7) (em) and (he), and 62.237, does not apply to 1st class cities under special charter.

(2) Any such city may adopt by ordinance this subchapter or any section or sections thereof, which when so adopted shall apply to such city.

(3) The revision of the general charter law by chapter 242, laws of 1921 shall not affect the application of any provisions of the general charter previously adopted by any 1st class city under special charter, but such provisions shall as to such cities retain the same force and application as they had before the enactment of chapter 242, laws of 1921.