Section 810 ILCS 5/8-206 - Completion or alteration of security certificate(a) If a security certificate contains the signatures necessary to its issue or transfer but is incomplete in any other respect:(1) any person may complete it by filling in the blanks as authorized; and(2) even if the blanks are incorrectly filled in, the security certificate as completed is enforceable by a purchaser who took it for value and without notice of the incorrectness.(b) A complete security certificate that has been improperly altered, even if fraudulently, remains enforceable, but only according to its original terms.P.A. 89-364, eff. 1/1/1996.