Section 20 ILCS 3110/6 - Bonds(a) Interest. All such bonds shall mature within 40 years from date, and shall bear interest at not more than the maximum rate authorized by the Bond Authorization Act, as amended at the time of the making of the contract, and may be sold by the Authority in such manner as they may deem to be in the best public interest. Such bonds shall be sold at such price that the interest cost of the proceeds therefor will not exceed the maximum rate authorized by the Bond Authorization Act, as amended at the time of the making of the contract, computed according to standard tables of bond values.(b) From what source payable. Such bonds shall be payable solely and only from (1) revenues to be derived from the operation of any such facilities acquired, constructed, completed, remodeled or equipped in whole or in part with the proceeds of such bonds; and (2) income to be derived from rental leases to State Departments, boards, commissions or other agencies, or from leases to others as provided above.(c) Execution and registration of bonds. Such bonds shall be executed by such officers of the Authority as shall be designated by the Authority, and shall be registered by the Auditor of Public Accounts or the Comptroller as his successor of the State of Illinois. Any bonds bearing the signature of officers in office at the date of signing thereof shall be valid and binding for all purposes, notwithstanding that before delivery thereof any or all such persons whose signatures appear thereon shall have ceased to be such officers.(d) Provisions contained in bond. Each such bond shall state upon its face that it is payable solely from revenues derived from the operation of facilities acquired, constructed, completed, remodeled or equipped in whole or in part with the proceeds of the sale of such bonds, including income to be derived from rental leases as provided above. Each bond shall state upon its face that it does constitute State debt of the State of Illinois within the meaning of the provisions of the Constitution and statutes of the State of Illinois. With respect to instruments for the payment of money issued under this Section either before, on, or after the effective date of this amendatory Act of 1989, it is and always has been the intention of the General Assembly (i) that the Omnibus Bond Acts are and always have been supplementary grants of power to issue instruments in accordance with the Omnibus Bond Acts, regardless of any provision of this Act that may appear to be or to have been more restrictive than those Acts, (ii) that the provisions of this Section are not a limitation on the supplementary authority granted by the Omnibus Bond Acts, and (iii) that instruments issued under this Section within the supplementary authority granted by the Omnibus Bond Acts are not invalid because of any provision of this Act that may appear to be or to have been more restrictive than those Acts.