Indiana Code Title 5. State and Local Administration § 5-1-5-15

(1) To provide for a reduction in the amount of lease rental payable by the lessee, or lessees, to be effective upon the redemption of the bonds being refunded;  or the happening of the events set forth in section 9 of this chapter if permitted by law and the covenants on the bonds to be refunded.

(2) To provide for extensions or reductions of the times set forth in the lease before the options of the lessee or lessees to purchase may be exercised to such times as may be agreed upon between the issuing body and the lessee or lessees.

(3) To provide that the lease rental payable by the lessee or lessees, after the redemption of all the bonds being refunded may be payable to the trustee under a trust indenture securing such refunding bonds.