Wis. Stat. § 74.63: Retention of tax certificate and other information.

Following issuance of a tax certificate under s. 74.57 and notice of issuance under s. 74.59, the treasurer shall retain all of the following:

(1) The tax certificate.

(2) The affidavit of mailing, executed under s. 74.59 (3).

(3) The tax roll upon which were included the real property taxes, special charges, special taxes or special assessments for which the tax certificate was issued.