In this part the following words have the meanings indicated. “Federal official” means a unit or official of the federal government charged with the collection of nontax liabilities payable to the federal government pursuant to 31 U.S.C. § 3716. “Nontax liability due the State” means a liability certified by the Secretary of Budget and Management to the Comptroller. “Refund” means an amount described as a refund of tax under the provisions of law that authorize its payment. “Vendor payment”: means any payment, other than a refund, made by the State to any person; includes any expense reimbursement to an employee of the State; and does not include a person’s salary, wages, or pension.