(1) An appellant who wishes another person (in this section referred to as the 'agent concerned') to act under the appellant's authority in relation to an appeal shall notify the Appeal Commissioners in writing accordingly and, for this purpose, shall provide the name and address of the agent concerned and any other information that the Appeal Commissioners may require.
(2) The authority referred to in subsection (1) of the agent concerned may be revoked by the appellant; where that authority is revoked by the appellant or it otherwise ceases to have effect, the appellant shall, in writing, notify the Appeal Commissioners of that fact forthwith.
(3) Unless and until the foregoing revocation or cesser of effect is notified in writing to the Appeal Commissioners, the Appeal Commissioners may treat any act that is required, or permitted to be performed, by the appellant under this Part as so performed by the appellant, if the act has been performed by the agent concerned.