Sch 15 para 5
(1) A person is within this paragraph (subject to paragraph 11) if— (a) he is employed by or in the service of a specified naval, military or air-force organisation of which the United Kingdom is a member; (b) he is so employed by reason of the United Kingdom's membership of that organisation; and (c) either— (i) he is in a country outside the British Islands, and his normal place of work under that employment is in that country; or (ii) sub-paragraph (i) does not apply, but he is in a country outside the British Islands and he came there wholly or partly for the purposes of his work under that employment. (2) In this paragraph “ specified ” means specified by order of the Secretary of State under this paragraph.