35 ILCS 516/210
No person, except a unit of local government, shall be eligible to bid or to receive a certificate of purchase who did not register with the county collector at least 5 business days in advance of the first day of the sale under Section 200. The collector may charge, for each registration, a fee of not more than $50 in counties with less than 3,000,000 inhabitants. Registration shall be made upon such forms and according to such regulations as the county collector deems necessary in order to effect complete and accurate disclosure of the identity of all persons beneficially interested, directly or indirectly, in each sale under Section 200. The information to be disclosed shall include, but not be limited to, the name, address, and telephone number of the purchaser to whom the clerk and collector will be requested to issue a certificate of purchase; if the purchaser is a corporation, the place of incorporation and the names and addresses of its shareholders unless the corporation is publicly held; if the purchaser is a partnership, the names and addresses of all general and limited partners; if the purchaser is doing business under an assumed business name, the county where such name is registered and the names, addresses, and telephone numbers of all persons having an ownership interest in the business; and the identity and location of any other tax delinquent mobile home owned by the bidder and purchaser.
Every application for certificate of purchase and form for registration authorized and required by this Section and Section 215 shall be executed under penalty of perjury as though under oath or affirmation, but no acknowledgement is required.
35 ILCS 516/210