16. Any security directive, enforcement notice or other notice or document required or authorised by any provision of this Order to be issued to, served on or given to any person may be issued, served or given —
(a)
by delivering it to him;
(b)
by sending it by registered post addressed to the person at his usual or last known place of residence or place of business, whether in Singapore or elsewhere; or
(c)
in the case of a body corporate, by delivering it to the secretary or similar officer of the body corporate at its registered or principal office in Singapore (or, if it has no office in Singapore, at its principal office, wherever it may be) or sending it by registered post to the secretary or similar officer of the body corporate at that office.