Wis. Stat. § 700.40
Chapter 261, laws of 1981, which created this section, states in section 3 that: The treatment of ss. 700.40 and 893.33(6m) by this act applies to:
(1) Any interest created after April 27, 1982 which complies with s. 700.40, whether designated as a conservation easement, covenant, equitable servitude, restriction, easement or otherwise.
(2) Any interest created prior to April 27, 1982 which would have been enforceable if created after April 27, 1982, unless retroactive application contravenes the constitution or laws of this state or of the United States.