5 C.F.R. § 1201.92

Criteria for certifying interlocutory appeals.

        The judge will certify a ruling for review only if the record shows that:

        (a) The ruling involves an important question of law or policy about which there is substantial ground for difference of opinion; and

        (b) An immediate ruling will materially advance the completion of the proceeding, or the denial of an immediate ruling will cause undue harm to a party or the public.

Official source