The document “NSF-331.4-Marking-table-for-BS-8418-2021-CCTV-systems-Aug-2021” provides a comprehensive marking table for the installation and maintenance of detector-activated video surveillance systems in accordance with BS 8418:2021 and BS EN 62676-4:2015. It outlines specific criteria for NSI auditors to assess compliance, detailing various sections that cover design documentation, commissioning, maintenance, and other critical aspects of system performance, with a scoring system for deviations that may result in demerit marks. The document serves as a guideline for NSI NACOSS Gold and NSI Systems Silver approved companies to ensure adherence to established standards.