Ill. Admin. Code tit. 71, § 2000.350
b) Failure of Bidder to sign its bid, but only if:
c) Failure of a Bidder to acknowledge receipt of an amendment to an Invitation for Bids, but only if:
A minor informality or irregularity is one which is a matter of form or pertains to some immaterial or inconsequential defect or variation of a bid from the exact requirement of the Invitation for Bids, the correction or waiver of which would not be prejudicial to other Bidders. The defect or variation in the bid is immaterial and inconsequential when its significance as to price, quantity, quality, or delivery is trivial or negligible when compared to the total cost or scope of the goods or services being procured. The Director of Purchasing shall either give the Bidder an opportunity to cure any deficiency resulting from a minor informality or irregularity in a bid or waive such deficiency, whichever is to the advantage of the Agency. Examples of minor informalities or irregularities of form include, but are not limited to: