Wis. Stat. § 229.831: Bonds not public debt.

(1) The state and the county and municipalities located wholly or partly within the district’s jurisdiction are not liable on bonds and the bonds are not a debt of the state or the county or any municipality located wholly or partly within the district. All bonds shall contain a statement to this effect on the face of the bond. A bond issue does not, directly or indirectly or contingently, obligate the state or a political subdivision of the state to levy any tax or make any appropriation for payment of the bonds.

(2) Nothing in this subchapter authorizes a district to create a debt of the state or the county or any municipality located wholly or partly within the district’s jurisdiction, and all bonds issued by a district are payable, and shall state that they are payable, solely from the funds pledged for their payment in accordance with the bond resolution authorizing their issuance or in any trust indenture or mortgage or deed of trust executed as security for the bonds. Neither the state nor the county or any such municipality is liable for the payment of the principal of or interest on a bond or for the performance of any pledge, mortgage, obligation or agreement that may be undertaken by a district. The breach of any pledge, mortgage, obligation or agreement undertaken by a district does not impose pecuniary liability upon the state or the county or any such municipality in the district’s jurisdiction or a charge upon its general credit or against its taxing power.

(3) Bonds issued by the district may be secured only by the district’s interest in any football stadium facilities, by income from these facilities, by proceeds of bonds issued by the district and by other amounts placed in a special redemption fund and investment earnings on such amounts, including any taxes imposed by the district under subch. V of ch. 77. The district may not pledge its full faith and credit on the bonds and the bonds are not a general obligation liability of the district.