Indiana Code Title 8. Utilities and Transportation § 8-10-1-4

(1) do not constitute a debt of the ports of Indiana, the state, or any political subdivision of the state, or a pledge of the faith and credit of the ports of Indiana, the state, or any political subdivision of the state;

(2) are payable solely from the funds pledged for their payment as authorized in this article, unless the bonds are refunded by refunding bonds issued under the provisions of this chapter, which shall be payable solely from funds pledged for their payment as authorized in this article;  and

(3) must contain on their face a statement to the effect that the bonds, as to both principal and interest, are not an obligation of the ports of Indiana, the state, or of any political subdivision of the state, but are payable solely from revenues pledged for their payment.