Chemical Weapons Convention term encompassing on-site inspection (including the continuous presence of inspectors) and monitoring with on-site instruments. Chemical weapons (CW) storage, production, and destruction facilities and Schedule 1 chemical facilities are subject to systematic verification. In addition, systematic verification may be applied to abandoned CW if deemed appropriate as a result of on-site inspection. Schedule 2 and 3 chemical plant sites, as well as discrete organic chemical plant sites, are subject to data monitoring and, if certain quantitative activity thresholds are met, on-site inspection.