4.15.—(1) An expert witness may only present information about matters which are necessary to further the purpose of the inquiry.
(2) A participant who has decided to instruct an expert witness must, as early as possible, lodge a note setting out—
(a)the identity of the witness to be instructed, if known;
(b)why the information to be presented by that witness is necessary to further the purpose of the inquiry;
(c)the broad terms of the instruction; and
(d)the expected completion date of any report.