This index was developed primarily to define the industrial and occupational classification systems adopted for the 1970 Census of Population. For each category in the classification systems it presents the individual titles constituting the particular category. Approximately 19,000 industry and 23,000 occupation titles are included. These titles represent a comprehensive listing of specific industries and occupations developed historically and maintained continuously by review of census and survey schedules. The index is divided into two sections, the first listing industry categories and their component industry titles and the second listing the occupation categories and their component titles. The classification systems and codes used are explained for the 215 industrial categories and for the 417 occupational categories listed. (MF)