35 ILCS 200/21-130

Use of figures and letters in advertisement and other lists. In all advertisements for the sale of properties for taxes or special assessments, and in entries required to be made by the clerk of the court or other officer, letters, figures, characters or property index numbers may be used to denote townships, ranges, sections, parts of sections, lots or blocks, or parts thereof, the year or the years for which the taxes were due, and the amount of taxes, special assessments, interest and costs. The county collector may subsequently advertise and obtain judgment on properties that have been omitted, or that have been erroneously advertised or described in the first advertisement.