Indiana Code Title 5. State and Local Administration § 5-1.2-4-16

Sec. 16. Any bonds issued by the authority under this article shall be executed by the manual or facsimile, except as otherwise provided in this article, signatures of the officers or agents of the authority that the authority designates.  If bonds are issued pursuant to a trust indenture, the manual authentication of each bond by the trustee shall be required.  If bonds are issued without a trust indenture or trustee, at least one (1) of the officers or agents of the authority shall manually execute each bond.  If any of the members or officers of the authority shall cease to be members or officers of the authority before the delivery of any bonds or coupons signed by them, their signatures or facsimiles shall nevertheless be valid and sufficient for all purposes, the same as if the members or officers had remained in office until the delivery.  Pending preparation of the definitive bonds, the authority may issue interim receipts or certificates, which must be exchanged for the definitive bonds.