Operation "Overlord" - Security During Post-Briefing Period. Report by J.I.C.

5. In order to meet the problem, the following are some of the measures taken:(a) After briefing, perimeter and interior guards will be established by S.O.S. and tactical units in order to prevent communication between briefed troops and persons not entitled to operational knowledge. (b) Pass systems have been developed, in accordance with local requirements, to ensure that only persons whose business compels their presence shall have access to "sealed" areas. (c) Marshalling Area Camps are being fenced in by wire barriers where such is considered necessary.