In Donovan v. West, 158 F.3d 1377 (Fed. Cir. 1998), cert. denied, U.S. , 119 S.Ct. 1255 (1999), the Court held that in conducting such a review, the Board is essentially reviewing the RO decision, as if on direct appeal, and therefore subsumes the initial RO decision. See Donovan, 158 F.3d at 1281-82. Donovan further explained that when the Board sua sponte reviews an Regional Office ("RO") decision "de novo" and finds no "error," it has essentially determined that no clear and unmistakable error ("CUE") in any form exists in the RO decision. Thus, this doctrine of delayed subsuming allows the Board to act on collateral review as if it is hearing a case on direct appeal (which it is not) and act as if it is hearing a collateral attack regarding CUE (when it is hearing a collateral attack based on new and material evidence).1 For example, the Donovan court stated that it agreed that the Board decision "`denying service connection was not limited to the question of whether a claim should be reopened i.e., a collateral attack, but extended to an analysis of the merits of the underlying question of service connection i.e., a direct appeal of the original claim.'" Donovan, 158 F.3d at 1381. The court further noted that "although the 1988 Board decision did not use the words `clear and unmistakable error,' we conclude that the Board determined that no such error infected the 1947 RO's decision." Id.