The citation may be served on the person charged by 1 of the following methods:in person; by certified mail, return receipt requested; by delivery to a person of suitable age and discretion who resides at the last-known address of the person charged; or for service on an occupant of the premises at which the violation occurred, by:posting on the main entrance of the premises; and mailing by regular mail to the person charged, at that person’s last-known address. The enforcement officer shall retain a copy of the citation and file it with the Department of Finance. Ord. 03-595