10 ILCS 5/4-4
The county clerk shall be ex officio the registration officer of such county and shall have full charge and control of the registration of voters within such county, where this Article 4 is in effect.
For the 3 days of any 1969 and 1970 re-registration and for precinct registrations hereinafter provided, 2 of the judges of election, no more than one from the same political party, theretofore duly appointed and confirmed as such and acting in each precinct, shall be designated by the county clerk to constitute a board of registration for each precinct, respectively, and each of such judges of election so designated shall serve as a judge of registration therein.
In counties over 1,000,000 population town or road district clerks, city or village clerks, their duly authorized deputies approved by the county clerk, and employees of the office of the county clerk may be appointed by the county clerk as deputy registration officers.
Such clerks appointed as deputy registration officers may accept registration of voters at their offices at any time that such registrations may be accepted by the county clerk, but shall not accept such registrations at any other place. Such deputy registration officers shall return any registrations accepted by them to the county clerk within 7 days after any registration is accepted by them.
Registration officers, deputy registration officers and judges of registration shall be officers of the court and the provisions of the laws of this State as to vacancies, removal and control (except as hereinafter provided), and punishment in case of misbehavior of judges of election shall apply to such registration officials.
Each registration officer including officers and judges of registration shall before entering upon his duties take and subscribe to the following oath or affirmation:
"I do solemnly swear (or affirm, as the case may be) that I will support the Constitution of the United States, and the Constitution of the State of Illinois, and that I will faithfully discharge the duties of the office of registration officer to the best of my ability, and that I will register no person nor cause the registration of any person except upon his personal application before me. ....................................... (Signature of Registration Officer)"
This oath shall be administered by the county clerk, or by one of his deputies, or by any person qualified to take acknowledgments and shall immediately thereafter be filed with the county clerk, except that judges of registration may administer such oath or affirmation to each other and such oath of office and all affidavits which have been signed and sworn to before them shall be returned to the office of the county clerk in an envelope provided for that purpose.
No registration official for a precinct or other place of registration shall, without urgent necessity, absent himself from the place of registration or revision of registration upon any day of registration or revision of registration whereby less than the number of persons necessary to conduct the registration or revision of registration shall be present during such hours of registration or revision of registration.
10 ILCS 5/4-4