38 C.F.R. § 19.22

A Substantive Appeal consists of a properly completed VA Form 9, “Appeal to Board of Veterans' Appeals,” or correspondence containing the necessary information. If the Statement of the Case and any prior Supplemental Statements of the Case addressed several issues, the Substantive Appeal must either indicate that the appeal is being perfected as to all of those issues or must specifically identify the issues appealed. The Substantive Appeal should set out specific arguments relating to errors of fact or law made by the agency of original jurisdiction in reaching the determination, or determinations, being appealed. To the extent feasible, the argument should be related to specific items in the Statement of the Case and any prior Supplemental Statements of the Case. The Board will construe such arguments in a liberal manner for purposes of determining whether they raise issues on appeal, but the Board may dismiss any appeal which fails to allege specific error of fact or law in the determination, or determinations, being appealed. The Board will not presume that an appellant agrees with any statement of fact contained in a Statement of the Case or a Supplemental Statement of the Case which is not specifically contested. Proper completion and filing of a Substantive Appeal are the last actions the appellant needs to take to perfect an appeal.