Income-tax Appellate Tribunal definitions clarify authorised representatives, Bench composition, Registrar roles and electronic contact terms. Definitions for Tribunal proceedings specify that an authorised representative includes persons authorised by an assessee under section 288 and persons appointed or authorised to represent the income-tax department; the Tribunal and Bench are defined to include the President, Senior Vice-President, Vice-President, Members sitting singly and Special Benches; Registrar includes Deputy and Assistant Registrars; 'prescribed form' is as per section 295 rules; and electronic/contact terms such as digital signature, e-mail address and Mobile number are recognised.