Where a federal, state, or local law requires a property owner to post a sign on the owner's property to warn of a danger or to prohibit access to the property either generally or specifically, the owner must comply with the federal, state, or local law to exercise that authority by posting a sign on the property. If the federal, state, or local regulation describes the form and dimensions of the sign, the property owner must comply with those requirements, otherwise, when not defined, the sign shall be no larger than two square feet and located in a place on the property to provide access to the notice that is required to be made.