10.—(1) Where a notice of an appeal has been received by the Registrar, and at the end of the period within which the appellant is required to send the additional material under rule 5,the Tegistrar is of the opinion—
(a)that it is so unlikely that the appeal will succeed on the basis of the notice and any additional material supplied that to proceed with it would be unfair to the Authority, or
(b)that the notice and any additional material supplied reveal no valid grounds of appeal, or that the appeal is otherwise misconceived,
he may, before sending the additional material to the Authority, serve a notice to that effect on the appellant.
(2) A notice under this rule must state the Registrar’s reasons for his opinion and inform the appellant—
(a)that the appeal will not proceed unless the appellant informs the Registrar in writing within fourteen days of the date of the notice that he wishes it to proceed, and
(b)that if he makes such a statement, and the appeal is subsequently withdrawn or decided against him, he may be liable, subject to the limitations imposed by rule 32, to pay the costs incurred by the Authority in connection with the appeal.
(3) Where a notice is given under this rule in relation to an appeal, unless the appellant informs the Registrar in writing before the end of the period of fourteen days starting with the date of the notice, that he wishes to proceed with the appeal—
(a)no further proceedings shall be taken in relation to the appeal, and
(b)at the end of the period, any interim order made or direction given under rule 15 immediately ceases to have effect.