Iowa Code § 804.2: Contents of arrest warrant.

The warrant must be directed to any peace officer in the state; give the name of the defendant, if known to the magistrate; if unknown, may designate “name unknown”; and must state by name or general description an offense which authorizes a warrant to issue, the date of issuing it, the county or city where issued, and be signed by the magistrate with the magistrate’s name of office.