65 ILCS 5/9-2-85
In counties having a population of less than 1,000,000, the collector of the municipality, not later than 5 days prior to the date fixed for application for judgment, shall make a return or report in duplicate upon forms to be provided by the county collector to the general officer of the county having authority to receive State and county taxes in the county in which the respective lots, tracts, and parcels of land are situated. Such report shall list all the land, town lots, and real property on which he has been unable to collect the special assessments or special taxes or installments, thereof, matured and payable or interest thereon, or interest due to the preceding January 2 on installments not yet matured on all warrants in his possession. Also contained in the report shall be a list of the amount of those delinquent special assessments or special taxes or installments and interest together with a brief description of the warrant or warrants received by him, authorizing the collection thereof. The original of this report shall be accompanied with the oath of the collector (1) that the list is a correct return and report of the land, town lots, and real property on which the special assessment or special tax (levied by the authority of the city or incorporated town or village of ...., as the case may be), or installments thereof, or interest, remains due and unpaid, (2) that he is unable to collect the same, or any part thereof, (3) that he has given the notice required by law that the specified warrants have been received by him for collection, and (4) that he has published an advertisement in the manner prescribed by law, giving notice that an application will be made on the date specified therefor for judgment against all of those delinquent lands, town lots, and real property.
65 ILCS 5/9-2-85