Criteria. The Secretary may revoke all or part of a delegation previously made to the OAH if the Secretary believes that the case might: Involve novel or unanticipated factual or legal issues; Have significant social or fiscal consequences; Involve policy issues of general applicability; or Be likely to have precedential value. Timing. The revocation may be made at any time before the earlier of: The issuance of a ruling on a substantive issue; or The taking of oral testimony from the first witness. Notice. The Secretary shall provide written notice of a revocation to all parties and the OAH. The written notice shall: Contain a brief statement of the reason for the revocation; Specify whether all or part of the delegation to hear the case is revoked; and If less than all of the delegation is revoked, specify the parts of the contested case for which the delegation has been revoked. Decision; Record. The Secretary's subsequent decision in the case shall reflect the fact that delegation to the OAH was revoked. A copy of the revocation notice shall be made a part of the record.