65 ILCS 5/1-1-4
This Code shall apply generally to all municipalities which are treated as properly incorporated under this Code as provided in the first paragraph of Section 1-1-3 and to all municipalities which are incorporated under this Code.
This Code shall also apply generally to all municipalities incorporated and now existing under a special charter except to the extent that this Code is in conflict with any provision in a special charter, and except as otherwise provided in subsection (1) of Section 1-1-2. In the event that there is a conflict between a provision in this Code and a provision in a special charter, the special charter shall govern except where any such charter conflicts with or is inconsistent with the general election law and except where a provision in this Code is stated to apply to municipalities incorporated under a special charter, or to municipalities whether incorporated under a general or special act, or words to that effect, or where it is otherwise made manifest that this Code or any other Illinois statute is intended to govern despite the inconsistent provisions in the special charter. A municipality incorporated under a special charter may, by ordinance or resolution, adopt the provisions of Sections 3.1-15-10, 3.1-20-5, and 3.1-20-22 of this Code.
However, if a particular section of this Code is limited to cities or villages or incorporated towns or any combination thereof, or to cities, villages, or incorporated towns of a specified type or any combination thereof, that intention shall prevail.
65 ILCS 5/1-1-4