Article 8 Amendment and supplementary grounds
With the leave of the Tribunal, the appellant may amend his notice of appeal or deliver supplementary grounds of appeal.
Paragraphs (1) and (3) of rule 5 above apply to an amended notice of appeal and to supplementary grounds of appeal provided under paragraph (1) above as they do to a notice of appeal.
Upon receipt of a copy of an amended notice of appeal or amended grounds of appeal under rule 5(1)(b) or (3)(a) above, the Commissioner may amend his reply to the notice of appeal, and must send the amended reply to the Tribunal and the appellant—
where he receives a copy of a notice of appeal under rule 5(1)(b) above, within 21 days of the date of that receipt, and
where he receives a copy of a notice of appeal under rule 5(3)(a) above, within such time, not exceeding 21 days from the date of that receipt, as the Tribunal may allow.
Rule 6(3) above applies to the periods referred to in paragraph (3) above.
Without prejudice to paragraph (3) above, the Commissioner may, with the leave of the Tribunal, amend his reply to the notice of appeal, and must send the amended reply to the Tribunal and the appellant.