On an application made to him under this section, the Secretary of State may certify that the applicant—
The Secretary of State may not issue a certificate of authorisation unless he is satisfied that the applicant—
A certificate of authorisation continues in force until such date, or the occurrence of such event, as may be specified in the certificate but may be suspended or revoked under paragraph 7 of Schedule 11.
A certificate which authorises the performance of both escort functions and custodial functions may specify one date or event for one of those functions and a different date or event for the other.
The Secretary of State may confer functions of detainee custody officers on prison officers or prisoner custody officers.
A prison officer acting under arrangements made under subsection (5) has all the powers, authority, protection and privileges of a constable.
Schedule 11 makes further provision about detainee custody officers.