Revision of tax orders allows a Commissioner level authority to stay and alter subordinate orders subject to strict time and appeal limits. Revisional authority (not below Commissioner) may examine records and, if a subordinate's order is erroneous, illegal, improper or prejudicial to revenue, may stay that order, hear the person, inquire further and pass any just order including enhancement, modification or annulment. The power is limited where the order has been appealed, where appeal periods or a two year limitation apply, where revision was previously taken, or where the order was passed exercising revisional powers. Periods of appellate consideration and judicial stays are excluded from limitation. 'Record' includes all records available at examination.