Authorization of representative requires a filed authorization letter before meetings; only one valid at a time and misconduct may debar. Regulation 46 requires parties to file a authorization letter or vakalatnama signed as specified before the Secretary prior to the ordinary meeting; only one authorization per party is valid at a time and a new filing revokes the earlier one. The Commission may debar representatives for misconduct, must record reasons in writing, and the Secretary may forward complaints against counsel to the relevant professional body. 'Misconduct' covers interference with due process, obstruction of orders, defamatory or defiant behaviour, and actions undermining Commission members or officers.