(1) This rule applies if, before any proceeding is started, 2 or more persons (the
"disputants" ) agree in writing on the following matters—(a) there is a dispute between them that will probably result in a proceeding and obtaining expert evidence immediately may help in resolving a substantial issue in the dispute;(b) the identity of an expert from whom a report should be obtained;(c) when the report must be prepared by the expert and given to the disputants;(d) liability for fees and expenses payable to the expert.
(2) The disputants may in writing jointly appoint the agreed expert to prepare a report giving an opinion on the issue.
(3) The appointment must be expressed to be made under this rule.
(4) The disputants may appoint the expert only if the expert has been made aware of the content of this part and consents to the appointment.
(5) Rule 428 (2) and (3) apply in relation to the report.
(6) Unless the court otherwise orders, in any proceeding started in the court between the disputants in which the issue is relevant, the expert is to be the only expert who, in relation to the disputants, may give evidence on the issue.