D.C. Mun. Regs. tit. 3, § 1507
1507.1 A person who has been nominated as a candidate for President or Vice President may withdraw his or her nomination by executing and filing with the Board, a notarized affidavit which states that the candidate irrevocably withdraws the candidacy for the office to which he or she has been nominated.
1507.2 In the event the affidavit is received less than forty-five (45) days before the election, the name of the person may not be excluded from the ballot.
SOURCE: Final Rulemaking published at 27 D.C. Reg. 2763 (June 27, 1980), incorporating the text of Proposed Rulemaking published at 27 D.C. Reg. 1929, 1944 (May 9, 1980).