21.—(1) The amendments to Part 19 made by rule 7 of these Rules apply as follows—
(a)rule 19.9 and rule 19.9A apply only to a derivative claim issued on or after 1st October 2007;
(b)rule 19.9B applies to the taking over of a derivative claim only where the relevant application for permission to take over the claim is filed on or after 1st October 2007;
(c)rule 19.9C—
(i)applies to a derivative claim issued on or after 1st October 2007; and
(ii)applies to the taking over of a derivative claim only where the relevant application for permission to take over the claim is filed on or after 1st October 2007;
(d)rule 19.9D applies to a derivative claim that arises in the course of other proceedings only if—
(i)rule 19.9A would apply to the claim if it were brought; or
(ii)rule 19.9B or 19.9C would apply to the taking over of the claim; and
(e)rules 19.9E and 19.9F apply to a derivative claim only if rule 19.9A, 19.9B or 19.9C also applies to the claim.
(2) The rules of court relating to a derivative claim (within the meaning of those rules) in force immediately before 1st October 2007 apply as if they had not been amended to any derivative claim in respect of which the claim form was issued before 1st October 2007.