THE COMPLETION OF THE ISOCORRAG PROGRAM, together with the extensive analyses that have been carried out on the results, has closed some of the gaps in our knowledge in the field of atmospheric corrosion. This was accomplished by having a large-scale and well-defined program that covered both corrosion results and environmental data for a major portion of the Earth's surface. The primary goal of the ISOCORRAG Program was to have such a data set for the revision of the ISO atmospheric corrosivity classification system.