Article 9
The tribunal shall, if practicable, secure the attendance at the hearing of any person from whom it has received a report on the appellant's case and in that case shall give the appellant and the Board an opportunity of putting question to such person:
Provided that the attendance of such person may be dispensed with if the appellant and the Board agree.
The tribunal may call any other person as a witness and in that case shall—
at the same time as it gives notice of the hearing under Rule 6 (1) (or as soon as may be practicable thereafter and in any event not less than seven days before such person is to be called) notify the appellant and the Board of his name; and
give the appellant and the Board an opportunity of putting questions to him at the hearing.