735 ILCS 5/4-204
The person claiming to have a lien under the provisions of Part 2 of Article IV of this Act may file in the circuit court, in the county where any such water craft may be found, a complaint, setting forth the nature of his or her claim, the amount due after allowing all payments and just offsets, the name of the water craft, and the name and residence of each owner known to the plaintiff; and when any owner or his or her place of residence is not known to the plaintiff, he or she shall so state, and that he or she has made inquiry and is unable to ascertain the same, which complaint shall be verified by the affidavit of the plaintiff or his or her agent or attorney. If the claim is upon an account or instrument in writing, a copy of the same shall be attached to the complaint.
735 ILCS 5/4-204