(1) An advance statement may be made at any time and must—
(a) be in writing; and
(b) be signed and dated by the person making the advance statement; and
(c) be witnessed by an authorised witness; and
(d) include a statement signed by the authorised witness stating that—
(i) in the opinion of the witness, the person making the advance statement understands what an advance statement is and the consequences of making the statement; and
(ii) the witness observed the person making the advance statement sign the statement; and
(iii) the witness is an authorised witness.
(2) An advance statement is effective from the time it is made until it is revoked.