This is a classified scheme for businesses world-wide, based on the 1987 US Standard
Industry Classification codes. THis is a hierarchical scheme for classifying
resource, manufacturing, wholesale and retail trades. It is strong on
some areas like mining, weak on others like entertainment.
This list merely registers homepage titles under one or more SIC codes,
so it's good for registering "Joe's Farm" under "Sheep Farming", or whatever.