Revision of orders under section 264 allows senior tax commissioners to call records and revise subordinate orders within prescribed limits. Section 264 authorises the Principal Chief Commissioner/Chief Commissioner/Principal Commissioner/Commissioner to call for records of subordinate orders (other than those under section 263), inquire and pass orders not prejudicial to the assessee. Revision may be suo motu or on the assessee's application, each subject to one year limitation rules, discretionary extension for sufficient cause, procedural exclusions for re hearing and court stays, and categorical restrictions where appeal rights exist, are pending, or have been exercised; a prescribed fee accompanies applications.