An indepth study of the FORTUNE 500 Corporations' libraries has revealed consistent characteristics across 27 industrial classifications, some of which parallel the divisions of professional associations, such as the Special Libraries Association. Partial profiles of Pharmaceutical, Aircraft, and Food Libraries are given as examples, with the proposals made that appropriate professional society units sponsor efforts to both complete the relevant profiles, and to determine how 139 of the FORTUNE 500 manage without libraries. Best estimates are that the 311 corporations spend between $108.8 and $145 million for library materials and services annually. (Author)