35 ILCS 200/21-115
The advertisement shall be published once at least 10 days before the day on which judgment is to be applied for, and shall contain a list of the delinquent properties upon which the taxes or any part thereof remain due and unpaid, the names of owners, if known, the total amount due, and the year or years for which they are due. In counties of less than 3,000,000 inhabitants, advertisement shall include notice of the registration requirement for persons bidding at the sale. Properties upon which taxes have been paid in full under protest shall not be included in the list.
The collector shall give notice that he or she will apply to the circuit court on a specified day for judgment against the properties for the taxes, and costs, and for an order to sell the properties for the satisfaction of the amount due.
The collector shall also give notice of a date within the next 5 business days after the date of application on which all the properties for the sale of which an order is made will be exposed to public sale at a location within the county designated by the county collector, for the amount of taxes, and cost due. The advertisement published according to the provisions of this Section shall be deemed to be sufficient notice of the intended application for judgment and of the sale of properties under the order of the court. A county with fewer than 3,000,000 inhabitants may, by joint agreement, combine its tax sale with the tax sale of one or more other contiguous counties; such a joint tax sale shall be held at a location in one of the participating counties. Notwithstanding the provisions of this Section and Section 21-110, in the 10 years following the completion of a general reassessment of property in any county with 3,000,000 or more inhabitants, made under an order of the Department, the publication shall be made not sooner than 10 days nor more than 90 days after the date when all unpaid taxes on property have become delinquent.
35 ILCS 200/21-115