((a)) A decision by the Board is subject to revision on the grounds of clear and unmistakable error. If evidence establishes the error, the prior decision shall be reversed or revised.
((b)) For the purposes of authorizing benefits, a rating or other adjudicative decision of the Board that constitutes a reversal or revision of a prior decision of the Board on the grounds of clear and unmistakable error has the same effect as if the decision had been made on the date of the prior decision.
((c)) Review to determine whether clear and unmistakable error exists in a case may be instituted by the Board on the Board’s own motion or upon request of the claimant.
((d)) A request for revision of a decision of the Board based on clear and unmistakable error may be made at any time after that decision is made.
((e)) Such a request shall be submitted directly to the Board and shall be decided by the Board on the merits.
((f)) A claim filed with the Secretary that requests reversal or revision of a previous Board decision due to clear and unmistakable error shall be considered to be a request to the Board under this section, and the Secretary shall promptly transmit any such request to the Board for its consideration under this section.