55 ILCS 5/5-6002
Any county is authorized to adopt by reference the provisions of any code or portions of any code as herein defined, without setting forth the provisions of such codes in full, provided that at least 3 copies of such code which is incorporated or adopted by reference are filed in the office of the county clerk and there kept available for public use, inspection, and examination. Any county is likewise authorized and empowered to adopt by reference the provisions of any public records, provided, likewise, that 3 copies of such public record are kept on file in the office of the county clerk as provided above for codes. The filing requirement herein prescribed shall not be deemed to be complied with unless the required copies of such code or public record are filed with the county clerk for a period of 15 days prior to adoption of the ordinance or resolution which incorporates such code or public record by reference.
55 ILCS 5/5-6002