HC Deb 06 March 1991 vol 187 c378

7. Where the use of firearms is justified in accordance with these rules members of the security forces shall identify themselves and shall give a clear warning of their intent to use firearms, with sufficient time for the warning to be observed, unless to do so would expose others or themselves to undue risk or would be clearly pointless or inappropriate in the circumstances.

8. The words "Army/Police: stop or I fire" or words to similar effect are to be used.