Ill. Admin. Code tit. 77, § 996.700
c) To receive reimbursement, the veterinarian shall submit to the Department a certificate, which is provided on the application/eligibility voucher. The application/eligibility voucher must have a Department approval code and authorization stamp indicating approval. The veterinarian certificate must be signed by the veterinarian and the companion animal owner or the feral cat colony manager. (Section 30 of the Act)