26 C.F.R. § 601.521
Any person desiring a conference in the office of the regional regulatory administrator in the Bureau of Alcohol, Tobacco, and Firearms of his region or of the Director, Bureau of Alcohol, Tobacco, and Firearms, in Washington, DC, relative to any matter arising in connection with his operations, will be accorded such a conference upon request. No formal requirements are prescribed for such conference. Where an industry member or other person is to be represented in conference, the representative must be recognized to practice as provided in paragraph (b) of § 601.502 . When a representative presents himself on behalf of an industry member or other person for the initial meeting in the office of a regional regulatory administrator in the Bureau of Alcohol, Tobacco, and Firearms or of the Director, Bureau of Alcohol, Tobacco, and Firearms, he must submit evidence of recognition; or he should state in his first letter or other written communication with such office whether he is recognized to practice, and should enclose evidence of such recognition. In the case of a qualified attorney or a qualified certified public accountant, the filing of the applicable written declaration described in paragraphs (b)(1) (i) and (ii) of § 601.502 shall constitute evidence of recognition. In the case of an enrollee, the filing of a notification, stating that he is enrolled to practice and giving his enrollment number or the expiration date of his enrollment card, shall constitute evidence of recognition.
26 C.F.R. §601.521