75 ILCS 5/3-4
When the electors of an incorporated town, village or township have voted to establish and maintain a public library as provided in Section 2-2, the corporate authorities of such incorporated town, village or township shall levy an annual tax for the establishment and maintenance of such library, not exceeding .15% of the value as equalized or assessed by the Department of Revenue. If the petition and ballots so specify in the original establishment as set forth in Section 2-2 of this Act, the corporate authorities may levy a tax in excess of .15%, not to exceed the rate specified in such establishment petition and ballot, but in any event not to exceed .60% of the value as equalized and assessed by the Department of Revenue. If the annual public library tax rate of an established library was increased above .12% up to .20% prior to 1972 as provided in this Act, the corporate authorities shall then levy up to an additional .03% above the increased rate approved at the referendum. Such tax rate may be increased to not to exceed .60% of the value, as equalized or assessed by the Department of Revenue, or the excess tax shall no longer be levied, if the electors of such incorporated town, village or township shall so determine by referendum at any regular election. Such referendum shall be petitioned for in the manner as the referendum for the establishment and maintenance of the library. Any tax levied pursuant to Section 3-9 shall be disregarded in applying the provisions of this Section.
The corporate authorities may also levy an additional tax of .02% of the value of all the taxable property in the incorporated town, village or township, as equalized or assessed by the Department of Revenue, for the purchase of sites and buildings, for the construction and equipment of buildings, for the rental of buildings required for library purposes, and for maintenance, repairs and alterations of library buildings and equipment. In any year in which the corporate authorities propose to levy such additional .02% tax, the corporate authorities shall adopt a resolution determining to levy such tax. Within 15 days after the adoption of the resolution, it shall be published at least once in one or more newspapers published in the incorporated town, village or township, or if no newspaper is published therein, then in one or more newspapers with a general circulation therein. In an incorporated town, village or township in which no newspaper is published, publication may instead be made by posting a notice in three prominent places. The publication or posting of the resolution shall include a notice of (1) the specific number of voters required to sign a petition requesting that the question of the adoption of the resolution be submitted to the electors of the incorporated town, village or township; (2) the time in which the petition must be filed; and (3) the date of the prospective referendum. The clerk of the incorporated town, village or township, shall provide a petition form to any individual requesting one. If no petition is filed with the corporate authorities within 30 days after publication or posting of the resolution, the incorporated town, village or township shall then be authorized to levy the tax. However, if within the 30 day period, a petition is filed with the corporate authorities, signed by electors of the incorporated town, village or township equal in number to 10% or more of the total number of registered voters in the incorporated town, village or township, asking that the question of levying such a .02% tax be submitted to the electors thereof, the question shall be submitted at a special or general election. Notice of this election shall be given as provided by the general election laws of this state in force at the time of the election, and the election shall be held in all respects in accordance with those laws. The ballot on which the proposition is submitted shall be in substantially the following form: "Shall the corporate authorities of (name of incorporated town, village or township) be authorized to levy an additional tax of ...% for the construction of buildings, provision of sites, etc., as determined by resolution dated (insert date)?". If a majority of votes cast upon the proposition are in favor thereof, the corporate authorities may levy the additional tax.
75 ILCS 5/3-4