10 ILCS 5/4-8.01
If an applicant for registration reports a permanent physical disability which would require assistance in voting, the county clerk shall mark all his registration cards in the right margin on the front of the card with a band of ink running the full margin which shall be of contrast to, and easily distinguishable from, the color of the card. If an applicant for registration declares upon properly witnessed oath, with his signature or mark affixed, that he cannot read the English language and that he will require assistance in voting, all his registration cards shall be marked in a manner similar to the marking on the cards of a voter who requires assistance because of physical disability, except that the marking shall be of a different distinguishing color. Following each election the cards of any voter who has requested assistance as a voter with a disability , and has stated that the disability is permanent, or who has received assistance because of inability to read the English language, shall be marked in the same manner.
10 ILCS 5/4-8.01