D.C. Mun. Regs. tit. 7, § 1537
1537.1 Any Board member recorded as having voted with the prevailing side on a question may move to reconsider the question at any time, except that in the case of a rule or regulation, reconsideration shall occur before the rule or regulation has become effective.
1537.2 Adoption of rules of organization and procedure and amendments thereto shall not be subject to reconsideration under this section. No motion to reconsider may be made with respect to a matter which has been the subject of a previous motion to reconsider, which motion was defeated.
1537.3 A motion to reconsider shall require the approval of a majority of the Board members present and voting.