Wis. Stat. § 631.45: Limitations on loss to be borne by insurer.

(1) General. An insurance policy indemnifying an insured against loss may by clear language limit the part of the loss to be borne by the insurer to a specified or determinable maximum amount, to loss in excess of a specified or determinable amount, to a specified percentage of the loss, which may vary with the amount of the loss, or by a combination of these methods. If the policy covers various risks, different limitations may be provided separately for each risk if the policy clearly so states.

(2) Property coinsurance. A policy indemnifying an insured against loss of or damage to property may limit the part of the loss to be borne by the insurer to a percentage of the total loss that corresponds to the ratio of the insured sum to a specified percentage of the value of the insured property.