(a) Notice regarding sidewalk repairs, sewer or water connections, dangerous structures, abating nuisances or any other act, the expense of which if performed by the City may be assessed against the premises under the provisions of these Codified Ordinances, shall be served:
(1) By delivering the notice to the owner personally or by leaving the same at his or her residence, office or place of business with some person of suitable age and discretion;
(2) By mailing such notice by certified or registered mail to such owner at his or her last known address; or
(3) If the owner is unknown, by posting such notice in some conspicuous place on the premises for five days.
(b) No person shall interfere with, obstruct, mutilate, conceal or tear down any official notice or placard posted by any City officer unless permission is given by such officer to remove such notice or placard.
(1975 Code Sec. 1.11)