Wis. Stat. § 182.23: Facsimile signatures on corporate obligations.

On any bond, note or debenture issued by a corporation organized or created under the laws of this state which is countersigned or otherwise authenticated by the signature of a trustee acting in connection with the issuance, the signatures of the officers of the corporation and its seal may be facsimiles. If any officer who has signed or whose facsimile signature has been placed upon a bond, note or debenture has ceased to be such officer before such bond, note or debenture is issued, it may be issued by the corporation with the same effect as if the former officer were such officer at the date of its issue.