Silver mining becomes a null set as it does not exist in Canada. Silver is mined only as a by product of lead and zinc mining in Canada. However these 4 digit industries are restored for national detail. However, CSIC 0821, Sand and Gravel Pits, is restored at the level of national detail. There are no known establishments primarily engaged in extracting clay in Canada, although extraction of clay exists by the manufacturers of clay products.
Peat extraction is of little statistical significance in Mexico.
Beneficiation of Other Nonferrous Metallic Ores, has been split out. This split will have little statistical impact as there is only a very small amount of nickel mining in Mexico. The creation of the Support Activities for Mining subsector in is an important change for Mexico, since such activities are not represented in the Mexican classification. The nickel ore mining part of 1987 SIC 1061, Ferroalloy Ores, Except Vanadium, has been combined with 1987 SIC 1021, Copper Ores, at the national level. This has a small statistical impact as production is relatively insignificant.