(1) Any notice authorised or required by this Act to be served on or given to any person by the Commissioner may -
(a) if that person is an individual, be served on him -
(i) by delivering it to him, or
(ii) by sending it to him by post addressed to him at his usual or last-known place of residence or business, or
(iii) by leaving it for him at that place;
(b) if that person is a body corporate or unincorporate, be served on that body -
(i) by sending it by post to the proper officer of the body at its principal office, or
(ii) by addressing it to the proper officer of the body and leaving it at that office;
(c) if that person is a partnership in Scotland, be served on that partnership -
(i) by sending it by post to the principal office of the partnership, or
(ii) by addressing it to that partnership and leaving it at that office.
(2) In subsection (1)(b) "principal office", in relation to a registered company, means its registered office and "proper officer", in relation to any b