Revision powers of Commissioner permit referral of departmental decisions to the appellate authority within prescribed procedural timelines. Section 84 authorises the Principal Commissioner or Commissioner of Central Excise to call for records of subordinate adjudicating proceedings to test legality or propriety and to direct the subordinate authority or officer to apply to the Commissioner of Central Excise (Appeals) for determination of specified points. Such directions must be issued within a prescribed period from communication of the adjudicating order, and any application made in compliance is to be heard and treated as an appeal under the Chapter, subject to the Chapter's appellate provisions; a saving clause preserves pre-amendment treatment of certain orders.