50 ILCS 465/25

The bonds shall bear the manual or facsimile signatures of any officers of the Authority that may be designated in the ordinance authorizing the bonds and the signatures constitute the valid and binding signatures of the officers, notwithstanding that before the delivery of and payment for the bonds any or all of the persons whose signatures appear thereon have ceased to be officers of the Authority. The validity of the bonds shall not be dependent on nor affected by the validity or regularity of any proceedings relating to the home mortgage loans acquired or made from proceeds of the bonds. A recital in the bonds that they are issued pursuant to this Act shall be conclusive evidence of their validity and of the regularity of their issuance.