75 ILCS 35/2

All bonds authorized to be issued by virtue of the foregoing section before being so issued, negotiated and sold shall be signed by the president and secretary of such board of directors, and shall be registered, numbered and countersigned by the supervisor of the township wherein such library is located. Such registry shall be made in a book to be kept for that purpose; and in such register shall be first entered the record of the election authorizing the directors to borrow money, and then a description of the bonds issued by virtue of such authority as to number, date, to whom issued, amount, rate of interest and when due.