6.—(1) Any notice required to be given or served on a person under this Act shall be addressed to the person concerned and shall be given or served on him in one of the following ways:—

(a) where it is addressed to him by name, by delivering it to him;

(b) by leaving it at the address at which he ordinarily resides or, in a case in which an address for service has been furnished, at that address;

(c) by sending it by post in a prepaid registered letter, addressed to him at the address at which he ordinarily resides or, in a case in which an address for service has been furnished, at that address;

(d) where the address at which he ordinarily resides cannot be ascertained by reasonable inquiry, by delivering it to some person over sixteen years of age resident in or employed on the land to which the notice relates or by affixing it in a conspicuous position on or near such land.

(2) Where the name of the owner or of the occupier (as the case may be) cannot be ascertained by reasonable inquiry, a notice may be addressed to “the owner” or “the occupier” (as the case may require) without naming him.

(3) For the purposes of this section, a company within the meaning of the Companies Acts, 1963 to 1986, shall be deemed to be ordinarily resident at its registered office, and every other body corporate and every unincorporated body shall be deemed to be ordinarily resident at its principal office or place of business.

(4) A person shall not at any time during the period of one month after a notice is affixed under subsection (1) (d) remove, damage or deface the notice without lawful authorisation.