4.—(1) A Part 4 notice (other than an emergency hazard notice) may provide for the operation of the notice to be suspended until a time, or the occurrence of an event, specified in the notice.
(2) The time specified under sub-paragraph (1) may, in particular, be the time when a person of a particular description begins, or ceases, to occupy any accommodation.
(3) The council may, for the purposes of this paragraph, accept from a person on whom the notice is served a written undertaking to take, or to refrain from taking, any action specified in the undertaking.
(4) If the council does so, the event specified under sub-paragraph (1) may, in particular, be a notified breach of that undertaking.
(5) In sub-paragraph (4) a “notified breach” is an act or omission by the person—
(a)which the council considers to be a breach of the undertaking, and
(b)which is notified to the person in accordance with the terms of the undertaking.