The Secretary shall serve a copy of a notice lodged with him under section 9 on-
(a) the respondent within 14 days after a notice of appeal is so lodged, or such longer period as the Chairman, on application, may allow in any particular case; and
(b) any person, other than the appellant, who appears to the Secretary to be a person who-
(i) is bound by the decision appealed against; or
(ii) before the decision appealed against was made, had made representations to the respondent in relation to the subject-matter of that decision,
within 28 days after a notice of appeal is so lodged, or such longer period as the Chairman, on application, may allow in any particular case.