Book: Standard Industrial Classification Manual (SIC). (Ref) HF 1042. S73 l987. {Use the "alpha" Index, to quick view key word(s) in its many contexts.}
Unveiled 1937, the SIC code system is the original definer of the economy and business/industrial activity; it is still used, following several revisions, today in spite of limitations. SIC uses 4 digit code scheme. The industry groups and sub-groups strongly mirror a time period dominated by agriculture/extractive activities, manufacturing, industrial and retail, and cover, in lesser degree, many service & professional business activities. SIC schema is establishment-based, meaning a single physical location where the occurring economic therein is its primary activity. For these recognized industries, the government amassed detailed statistics in areas of: payroll, employment, profits, capital investments, and other data.
Increasingly subdivided, the SIC macro-level industrial groups are:
Ex: A "bicycle/repair shop business" is classed SIC #5941, Sporting Goods Stores & Bicycle Shops. See the SIC description: #5941.
Limitations/Weakness: Over time SIC codes & revisions lagged behind and did not adequately reflect many new, emerging business venture of the late 20th century. Codes heavily favored manufacturing. Existing code descriptions were restrictive as defined, excluded or failed to precisely accommodate new economy sectors, new technologies, or accompanying new "internet-age" business & services endeavors; the codes did not embrace them in a meaningful way or give them distinct recognition. SIC's limiting, rigid framework gathered many unrelated "info-age" industries/endeavors into similar categories, lacking precision of description or conceptual relevance of why a category was chosen. Production of new, high-tech products such as "computers" could be SIC grouped as "Industrial Machinery & Electrical Equipment", but not in a unique category by itself. Over time SIC shortcomings became restrictive, unrecognizing, and too conservative; it became more apparent a newer, more relevant classification scheme was needed.
The web offers many venues to search known SIC codes or by keyword. One government site is the Labor Department's branch, OSHA.