D.C. Mun. Regs. tit. 23, § 1712
1712.1 Any offer of proof made in connection with an objection to any ruling of the Board which rejects or excludes proffered oral testimony shall consist of a statement for the record of the substance of the evidence which the party contends would be established by the testimony.
1712.2 If the excluded evidence is documentary, a copy of the written evidence shall be marked for identification and shall constitute the offer of proof.
1712.3 The document shall be retained by the Board as part of the record for purposes of an appeal.
SOURCE: The Alcoholic Beverage Control Board Rules of Procedures Amendments of 1980, effective March 5, 1981 (D.C. Law 3-146; 27 DCR 4753 (October 31, 1980)); as amended by Final Rulemaking published at 35 DCR 4947 (June 24, 1988); as amended by Final Rulemaking published at 51 DCR 4309 (April 30, 2004); as amended by Final Rulemaking published at 55 DCR 12991 (December 26, 2008 – Part 2).