4. In Order 6, rule 8, for paragraph (1) there shall be substituted the following—
“(1) For the purposes of service, a writ (other than a concurrent writ) is valid in the first instance—
(a)if an Admiralty writ in rem, for 12 months;
(b)where leave to serve the writ out of the jurisdiction is required under Order 11, for 6 months;
(c)in any other case, for 4 months
beginning with the date of its issue.”.