38 C.F.R. § 20.202
(b) Review options. Upon filing the Notice of Disagreement, a claimant must indicate whether the claimant requests:
(c)
(g) Response required from claimant—(1) Time to respond. The claimant must respond to the Board's request for clarification on or before the later of the following dates:
(i) Representatives and fiduciaries. For the purpose of the requirements in paragraphs (f) through (h) of this section, references to the “claimant” include reference to the claimant or his or her representative, if any, or to his or her fiduciary, if any, as appropriate.
(Authority: 38 U.S.C. 7105)
(Approved by the Office of Management and Budget under control number 2900-0674)