(a) Where the respondent requests a hearing in accordance with § 71.60, a written answer shall be filed with the administrative law judge and served on the appropriate TTB officer within 15 days after service of the designation of the administrative law judge.

(b) Where no hearing is requested, the respondent shall file a written answer with the appropriate TTB officer within 15 days after service of a citation.

(c) An answer shall contain a concise statement of the facts that constitute his grounds for defense. The hearing may be limited to the issues contained in the citation and the answer. The administrative law judge, or appropriate TTB officer as the case may be, may, as a matter of discretion, waive any requirement of this section.

(d) Answers need not be filed in application proceedings.