NSI Technical Bulletin No. 0007 provides guidance on the application of the last paragraph of sub-clause 5.1.1.3 of BS 5979:2007, specifically regarding the use of layered security for Alarm Receiving Centres (ARCs) operational before June 30, 2008. It outlines the criteria for demonstrating that an equivalent standard of protection can be achieved through layered security methods, as opposed to traditional physical security measures, and details the inspection process for NSI Inspectors assessing compliance for ARC Gold approval. The bulletin also emphasizes the importance of evaluating the effectiveness of layered security in resisting or delaying criminal attacks. Manual review recommended for complete details.