No information shall be included in a register kept or maintained by the appropriate agency under any provision of this Act if and so long as, in the opinion of the Secretary of State, the inclusion in such a register of that information, or information of that description, would be contrary to the interests of national security.
The Secretary of State may, for the purpose of securing the exclusion from registers of information to which subsection (1) above applies, give to the appropriate agency directions—
and no information referred to the Secretary of State in pursuance of paragraph (b) above shall be included in any such register until the Secretary of State determines that it should be so included.
The appropriate agency shall notify the Secretary of State of any information it excludes from a register in pursuance of directions under subsection (2) above.
A person may, as respects any information which appears to him to be information to which subsection (1) above may apply, give a notice to the Secretary of State specifying the information and indicating its apparent nature; and, if he does so—