16(1)The Secretary of State may by order make provision requiring a person to whom this paragraph applies, if required to do so by an examining officer, to complete and produce to the officer a card containing such information in such form as the order may specify.
(2)An order under this paragraph may require the owners or agents of a ship or aircraft employed to carry passengers for reward to supply their passengers with cards in the form required by virtue of sub-paragraph (1).
(3)This paragraph applies to a person—
(a)who disembarks in Great Britain from a ship or aircraft which has come from the Republic of Ireland, Northern Ireland or any of the Islands,
(b)who disembarks in Northern Ireland from a ship or aircraft which has come from Great Britain, the Republic of Ireland, or any of the Islands,
(c)who embarks in Great Britain on a ship or aircraft which is going to the Republic of Ireland, Northern Ireland or any of the Islands, or
(d)who embarks in Northern Ireland on a ship or aircraft which is going to Great Britain, the Republic of Ireland, or any of the Islands.