Iowa Code § 8A.515: Warrants — form.

A warrant shall bear on its face the signature of the director or its facsimile, or the signature of an assistant or its facsimile in case of a vacancy in the office of the director; a proper number, date, amount, and name of payee; a reference to the law under which it is drawn; whether for salaries or wages, services, or supplies, and what kind of supplies; and from what office or department, or for what other general or special purposes; or in lieu thereof, a coding system may be used, which particulars shall be entered in a warrant register kept for that purpose in the order of issuance; and as soon as practicable after issuing a warrant register, the director shall certify a duplicate of it to the treasurer of state.