20.3.—(1) This rule applies to the intimation of a devolution issue on a relevant authority under—
(a)paragraph 5 of Schedule 6;
(b)paragraph 23 of Schedule 10;
(c)paragraph 14(1) of Schedule 9.
(2) When a devolution issue is raised, the party raising it must intimate the devolution issue to the relevant authority unless the relevant authority is a party to the appeal.
(3) Within 14 days after intimation, the relevant authority may give notice to the Clerk that it intends to take part in the appeal as a party under—
(a)paragraph 6 of Schedule 6;
(b)paragraph 24 of Schedule 10;
(c)paragraph 14(2) of Schedule 9.