(1) If a document is being amended under
this part, the amendment takes effect on and from the date of the document
being amended.
(2) However, an amendment including or substituting a cause of
action arising after the proceeding started takes effect on and from the date
of the order giving leave.
(3) Despite subrule (2) , if an amendment
mentioned in subrule (2) is made, then, for a limitation period, the
proceeding as amended is taken to have started when the original proceeding
started, unless the court orders otherwise.
