10 ILCS 5/6-67

Upon application to vote at a primary election each registered elector shall sign his name or mark and write his address on a certificate substantially the same as that used in the general election except that it shall have a place for party affiliation which is to be filled in by the elector, or by the officer in charge if the elector is unable to write. Such certificates when checked and initialed by the judge in charge, shall constitute the primary poll record. Such certificates at the close of the primary election shall be placed in an envelope, sealed and returned with the ballots. Nothing herein shall be construed to conflict with sections 7-44 and 7-45 of Article 7 of this Act.