(1) The sum of the principal amount of any refunding revenue bonds may exceed the principal amount of the revenue obligations to be refunded thereby by such amount as is useful to effect the refunding if the sum of the aggregate principal and net interest cost of the refunding revenue bonds for the period ending on the scheduled final maturity date of the revenue obligations to be refunded, without regard to any redemptions that may be made prior to such scheduled maturity date, is the same or less than the aggregate principal and net interest cost of the revenue obligations to be refunded for the same time period, excluding from the computation of the aggregate principal and net interest cost of the refunding revenue bonds any interest on the obligations to be refunded in arrears or about to become due and payable which is capitalized with the proceeds of the refunding revenue bonds and any interest on the refunding revenue bonds which is capitalized with the proceeds of the refunding revenue bonds. The principal amount of any general obligation refunding bonds shall not exceed the original authorized principal amount of the general obligations to be refunded. Except for refunding bonds where the indebtedness refunded was incurred pursuant to subsection (3) of section 6 of article XI of the state constitution, the principal amount of any general obligation bonds issued to refund outstanding revenue obligations shall not exceed the outstanding principal amount of the revenue obligations to be refunded, except to the extent that a larger principal amount of refunding bonds is authorized at an election pursuant to section 11-56-106 (3) or in the manner otherwise provided by law for incurring new indebtedness.

(2) Neither the principal of nor the interest on any special obligation refunding bonds issued in conjunction with any other refunding bonds pursuant to this article shall be considered when making any of the computations required by subsection (1) of this section.

(3) The principal amount of the refunding bonds may also be less than or the same as the principal amount of the obligations being refunded, so long as provision is duly and sufficiently made for payment in full and discharge of such refunded obligations.

(4) As the governing body may determine, any refunding bonds issued under this article shall:

(a) Be of a convenient denomination;

(b) Mature at such time not exceeding forty years from the date of said bonds as determined by the governing body;

(c) Bear interest, which may be evidenced by one or more sets of coupons, at a specified rate, payable annually or semiannually, but the first interest payment may be for interest accruing for any other period not to exceed three years;

(d) Be made payable, both principal and interest, in lawful money of the United States, at such place as determined by the governing body;

(e) Be negotiable in form and executed in substantially the same manner as prescribed for other bonds of such public body.

(5) The right to redeem all or part of said refunding bonds prior to their maturity, and the order of any such redemption, may be reserved in the ordinance or resolution of the governing body, as the case may be, authorizing the issuance of the bonds and, if so reserved, shall be set forth on the face of said bonds. Such redemption may be with or without the payment of a premium not exceeding five percent of principal, as determined by the governing body.

(6) Any ordinance or resolution authorizing, or any escrow agreement or trust indenture or other instrument appertaining to, any refunding bonds issued under this article may provide that each refunding bond shall recite that it is issued under authority of this article. Such recital shall conclusively impart full compliance with all of the provisions and limitations of this article, and all refunding bonds issued containing such recital shall be incontestable for any cause whatsoever after their delivery for value.