35 ILCS 200/18-30: Books by township.

In counties not under township organization, the collector's books shall be made up by congressional townships; but fractional townships may be added to full townships, at the discretion of the county board. In counties under township organization, the books shall correspond with the organized townships. Separate books may be made for the collection of all taxes within the corporate limits of cities, incorporated towns and villages. These books shall be in addition to the tax book provided for in this Code, for the use of county collectors, for collecting taxes against railroad property.