65 ILCS 5/11-121-5
To secure the payment of any or all of such revenue bonds or certificates and for the purpose of setting forth the covenants and undertakings of the municipality in connection with the issuance thereof, and the issuance of any additional revenue bonds or certificates payable from such revenues or income, as well as the use and application of the revenues or income to be derived from the operation of local transportation facilities within such municipality, including but not limited to the operation of all subways owned by such municipality, the municipality may execute and deliver a trust agreement or agreements or all such covenants and undertakings to secure the payment of the bonds or certificates may be included in the ordinance authorizing the bonds or certificates. However, no lien upon any physical property of the municipality shall be created thereby. A remedy for any breach or default of the terms of any such trust agreement or ordinance by the municipality may be by mandamus proceedings in any court of competent jurisdiction to compel performance and compliance therewith, but the trust agreement or ordinance may prescribe by whom or upon whose behalf such action may be instituted. Under no circumstances shall any revenue bonds or certificates issued by the municipality hereunder be or become an indebtedness or obligation of the municipality within the purview of any constitutional limitation or provision. It shall be plainly stated on the face of each revenue bond and certificate that it does not constitute such an indebtedness or obligation, but is payable solely from the revenues or income as aforesaid.
In case any officer whose signature appears on any bond or certificate or interest coupon, issued under this Division 121 ceases to hold his office before delivery thereof, his signature shall be valid and sufficient for all purposes with the same effect as if he had remained in office until delivery thereof.
65 ILCS 5/11-121-5