Service of notices, etc.
18. Any document or other communication which is required or authorised by these Regulations to be given, issued, made or sent to any person may be given, issued, made or sent–
(a)by delivery to that person; or
(b)by sending it by recorded delivery addressed to him at his usual or last known address; or
(c)where that person is represented by a solicitor, by sending it by recorded delivery to the solicitor at his usual or principal professional address; or
(d)in the case of the Joint Committee by sending it by post in a prepaid letter to their secretary.