D.C. Mun. Regs. tit. 8-B, § 3232
3232.1 Unless the solicitation provides otherwise, a bid may be responsive even though the bidder specifies that award will be accepted only on all, or a specified group, of the items .
3232.2 Bidders shall not be permitted to withdraw or modify an "all or none" qualification after bid opening because "all or none" qualifications are substantive and affect the rights of other bidders.
SOURCE: Final Rulemaking published at 39 DCR 2566 (April 10, 1992).