3.—(1) Any notice served under these Regulations shall be in writing and may be amended, suspended or revoked in writing at any time.
(2) Any such notice may be served by—
(a)delivering it to the person;
(b)leaving it at the person’s usual or last known address; or
(c)sending it by post to the person at that address.
(3) If the name or address of any occupier of premises on whom a notice is to be served under these Regulations cannot, after reasonable inquiry, be ascertained, the notice may be served by leaving it conspicuously affixed to a building or object on the premises.