19. The Tribunal must serve a copy of the notice of decision and any directions given under rule 27(2)(b) of the Principal Rules on every party to the appeal—
(a)if submissions were filed in response to the application under rule 17(b), not later than 1 day after they were filed; or
(b)if no submissions were filed within the period specified in rule 17(b), not later than 1 day after the end of that period.