(1) Such refunding bonds shall be authorized by a resolution fixing the date, the denominations, the rate of interest on individual bonds, the maturity dates which shall not be more than twenty-five years after the date of such refunding bonds, and the place of payment within or without the state of Colorado, of both principal and interest, and prescribing the form of such refunding bonds. Such bonds shall be negotiable in form and executed in the same manner as prescribed for other school district bonds. At the discretion of the board, any such bonds may be issued with privileges for registration for payment as to principal or interest, or both.

(2) The interest accruing on such refunding bonds may be evidenced by interest coupons thereto attached in substantially the same form as prescribed for other school district bonds, and, when so executed, such coupons shall be the binding obligations of the district according to their import. Such refunding bonds shall mature serially, commencing not later than five years after the date of such bonds and maturing during a period not exceeding twenty-five years after the date thereof. The amount of such maturities shall be fixed by the board of education and specified in the resolution authorizing the issuance of the refunding bonds. The right to redeem all or part of said bonds prior to their maturity, and the order of any such redemption, may be reserved in the resolution authorizing the issuance of bonds and shall be set forth on the face of said bonds. Interest on refunding bonds issued on or after July 1, 1973, pursuant to this article shall be exempt from Colorado income tax.