(1) A mailing returned as undeliverable as provided in sections sixteen, seventeen and twenty of this article; or
(2) Information obtained through a systematic purging program as provided in sections twenty-four and twenty-five of this article.
(b) A confirmation notice shall be sent by first class, forwardable mail and shall include a pre-addressed, postage prepaid or business reply return card on which the registrant may state his or her current address, together with a notice prescribed by the secretary of state to meet the specific requirements of Section 8(d)(2) of the "National Voter Registration Act of 1993" (42 U.S.C. 1973gg).