A. The ordinance authorizing the issuance of refunding bonds for an improvement district shall describe the:
(1) details of the issue;
(2) form of the refunding bonds and interest coupons, if any;
(3) fund from which the principal and interest of the refunding bonds will be paid; and
(4) manner in which the bonds are to be issued.
B. The refunding bonds may:
(1) be issued in an amount less than, equal to or greater than the principal amount of improvement district bonds being refunded;
(2) not bear a rate of interest greater than the rate of interest borne by the assessments providing security for the refunding bonds if secured by assessments;
(3) become due and payable in regular numerical order;
(4) not be issued for a period of more than twenty years from the date of issuance; and
(5) be payable from substitute security or from the same funds that were applicable to the payment of the bonds being refunded.
C. The refunding bonds may be:
(1) sold at a public or private sale at a discount; or
(2) exchanged, dollar for dollar, for the improvement district bonds being refunded.