12.—(1) Subject to the provisions of these Rules, a tribunal may regulate its own procedure.
(2) A tribunal may –
(a)before granting an application under rule 5 or 10 require the party making the application to give notice thereof to the other party;
(b)either on the application of any person or of its own motion, direct any other person to be joined as a party to the appeal (giving such consequential directions as it considers necessary), but may do so only after having given to the person proposed to be joined a reasonable opportunity of making written or oral objection;
(c)make any necessary amendments to the description of a party in the Register and in other documents relating to the appeal;
(d)if the appellant shall at any time give notice of the abandonment of his appeal, dismiss the appeal;
(e)if the parties agree in writing upon the terms of a decision to be made by the tribunal, decide accordingly.
(3) A chairman may postpone the day or time fixed for, or adjourn, any hearing and vary any such postponement or adjournment.
(4) Any act required or authorised by these Rules to be done by a tribunal may be done by a chairman except –
(a)the granting of an extension of time under rule 2(2);
(b)the hearing of an appeal under rule 7;
(c)an act required or authorised to be so done by rule 8 or 9 which the rule implies is to be done by the tribunal which is hearing or heard the appeal;
(d)the hearing of an application under rule 10(1), and the variation or revocation of a decision, and ordering of a re-hearing, under rule 10(7).