50 ILCS 810/2
When the building code department of a municipality or county determines a building code violation exists it shall cause a notice of such violation to be posted in a conspicuous place near the main entrance of such building. The notice shall be at least 9 inches in height and 14 inches in width and at the top thereof in large letters shall state "Notice of Violation". The text of the notice shall contain a reference to the provision of the building code violated and may contain such other information respecting the nature of the violation as the building code department deems advisable.
Upon removal of the cause of the violation for which the notice is posted, the building code department shall forthwith remove the notice. Any other person removing any such notice or defacing such notice is guilty of a petty offense and shall be fined not to exceed $100.
50 ILCS 810/2