This document specifies a chart rating system based on standard charts that provides a means of defining levels of performance of anodic oxidation coatings on aluminium and its alloys that have been subjected to corrosion tests. This rating system is applicable to pitting corrosion resulting from accelerated tests, exposure to corrosive environments, and practical service tests. This document takes into account only pitting corrosion resulting from penetration of the protective anodic oxidation coating. NOTE ISO 8994[1] describes a similar rating system based on defined grids.