In this Chapter—

• “certified”, in relation to a section 8(4) certificate, means of a description certified by the certificate as a description of material the examination of which the Secretary of State considers necessary;

• “external communication” means a communication sent or received outside the British Islands;

• “intercepted material”, in relation to an interception warrant, means the contents of any communications intercepted by an interception to which the warrant relates;

• “the interception subject”, in relation to an interception warrant, means the person about whose communications information is sought by the interception to which the warrant relates;

• “international mutual assistance agreement” means an international agreement designated for the purposes of section 1(4);

• “related communications data”, in relation to a communication intercepted in the course of its transmission by means of a postal service or telecommunication system, means so much of any communications data (within the meaning of Chapter II of this Part) as—

  1. a

     is obtained by, or in connection with, the interception; and

  2. b

     relates to the communication or to the sender or recipient, or intended recipient, of the communication;

• “section 8(4) certificate” means any certificate issued for the purposes of section 8(4).