38 CFR §21.4003
The revision of a decision on which an action was predicated will be subject to the following sections:
- (a)Clear and unmistakable error, § 3.105(a) of this chapter;
- (b)Difference of opinion, § 3.105(b) of this chapter;
- (c)Character of discharge, § 3.105(c) of this chapter;
- (d)Severance of service connection, § 3.105(d) of this chapter;
- (e)Veteran no longer totally and permanently disabled, § 21.4135(o).