38 C.F.R. § 19.32 Closing of appeal for failure to respond to Statement of the Case.
Title 38 - Pensions, Bonuses, and Veterans' Relief
The agency of original jurisdiction may close the appeal without notice to an appellant or his or her representative for failure to respond to a Statement of the Case within the period allowed. However, if a Substantive Appeal is subsequently received within the 1-year appeal period (60-day appeal period for simultaneously contested claims), the appeal will be considered to be reactivated. (Authority: 38 U.S.C. 7105(d)(3))
Title 38: Pensions, Bonuses, and Veterans' Relief
PART 19—BOARD OF VETERANS' APPEALS: APPEALS REGULATIONS
Subpart B—Appeals Processing by Agency of Original Jurisdiction
§ 19.32 Closing of appeal for failure to respond to Statement of the Case.

