15.2.—(1) No person may file expert evidence unless the court or a practice direction permits, or if it is filed with the application form and is evidence—
(a)that P is a person who lacks capacity to make a decision or decisions in relation to the matter or matters to which the application relates;
(b)as to P's best interests; or
(c)that is required by any rule or practice direction to be filed with the application form.
(2) An applicant may only rely on any expert evidence so filed in support of the application form to the extent and for the purposes that the court allows.
(Rule 9.4(a) requires the applicant to file any evidence upon which the applicant wishes to rely with the application form.)