§ 179.00 Model forms of obligations. The model form of a coupon bond and the model form of a note payable to bearer contained in schedule B annexed hereto may be used, but this section shall not be construed to prevent or invalidate the use of other forms in lieu thereof. Both of such forms provide for the conversion of the obligation into a registered obligation and also contain a provision permitting the redemption of the obligation prior to maturity by the municipality, school district or district corporation issuing such obligation.