10 ILCS 5/6-58
Following each general election occurring in November of even numbered years, beginning in 1940, the board of election commissioners shall examine the registration records and shall send to every voter who has not voted during the last four years, a notice through the mails, substantially as follows:
NOTICE OF SUSPENSION OF REGISTRATION
"You are hereby notified that your registration will be cancelled according to law for failure to vote during the last four years, unless you apply for reinstatement within thirty days. You may reinstate your registration by signing the statement below and returning it to this office or by making application in person to do so."
"APPLICATION FOR REINSTATEMENT OF
REGISTRATION
I hereby certify that I still reside at the address from which I am registered and apply for reinstatement of my registration:
Signed ....
Present address ....
Date ...."
In case the elector is unable to sign his name, the application for reinstatement shall be made at the office of the board of election commissioners.
After the expiration of thirty days the board of election commissioners shall cancel the registration of all electors thus notified who have not applied for reinstatement. A proper entry shall be made on the registration record for all electors whose registration is reinstated. Any elector whose registration has been cancelled for failure to vote may register again by making application therefor in the manner provided by this Article.
When a registration is cancelled under this or other sections of this Article, a proper entry shall be made upon the face of the original and duplicate records, which shall then be placed in a file of cancelled registrations and shall be preserved for two years from date of cancellation.
The Board of Election Commissioners shall, however, keep the cancelled cards in a suspense file for 2 years and reinstate them at any time within such 2 year suspense period, when a person's registration is cancelled under this or other Sections of this Article for failure to apply for reinstatement or to appear in proper time, and there is sufficient subsequent showing that he is a duly qualified elector.
10 ILCS 5/6-58