Data are not included for agricultural production, railroad, most government, or household employment. (Government liquor stores and wholesale liquor establishments operated by state and local governments as well as government hospitals are included.) Employees on ocean-borne vessels or in foreign countries are also not included. The classification for industrial sector is further descibed in the government's revised 1987 Standard Industrial Classification (SIC) system. Data which would "disclose the operations of an individual employer" are not released (Title 13, Section 9, of the United States Code). Because the data are based upon the entire universe of establishments, rather than a sample, they are not subject to sampling errors.

Seven industries, listed in descending order by their employment nationally, are covered:

• Service
  Number employed in service establishments. Examples of businesses the Census classifies in this category are overnight accommodations (hotels and motels, trailer parks and campsites), personal services (such as laundry (including coin-operated), drycleaning, beauty and barber shops, shoe repair and shoeshine parlors, funeral services, photographic studios, tax return prepatation), business services (advertising agencies, photocopying and duplication, computer and data processing services, stenographic services, credit reporting services, direct mail advertising services, equipment rental and leasing, building maintenance services, detective and armored car services, security systems services, news syndicates), auto services (rental, leasing, repair, carwashes), miscellaneous repair services (television and radio repair, refrigeration service and repair, reupholstery and furniture repair, welding repair, electric repair), entertainment services (motion pictures production and distribution, motion picture theaters, video tape rental, dance studios, theatrical productions, bowling centers, commercial sports, racing, physical fitness facilities, golf courses, amusement parks), health services (medical, dental, physicians, chiropractors, optometrists, hospitals, medical and dental laboratories, home health care services), legal services, educational services (schools, universities, libraries), social services (individual and family servicecs, job training, child car, residential care), museums (including art galleries, botanical and zoological gardens), membership organizations (business, professional, labor, civil, political, religious), engineering and management services (architectural, surveying, accounting and bookkeeping, testing, management and public relations).

• Retail Trade
  Number employed in retail trade. Examples of businesses the Census classifies in this category are building materials and garden supplies, general merchandise storers, food stores, automobile dealers and service stations, apparel and accessory stores, furniture and homefurnishings stores, eating and drinking places, and miscellaneous retail (including drug stores, liquor stores, used merchandise, book stores, jewelry stores, hobby and craft stores, gifts and novelty stores, luggage and leather goods, catalog and mail-order houses, fuel dealers, florists, tobacco stores, news dealers and newsstands, optical goods stores).

• Manufacturing
  Number employed in manufacturing. Examples of businesses the Census classifies in this category are the manufacture of food and kindred products (including meat packing plants, dairies, grain mills, wineries), tobacco products, textile mills, and production of apparel and other textile products, lumber and wood products (including logging, sawmills and planing mills, millwork, mobile homes, prefabricated wood buildings), production of furniture and fixtures, the production of paper and allied products (including pulp mills, paper mills, paperboard mills and manufacture of corrugated boxes, stationary), printing and publishing, chemical and allied products, petroleum and coal products, rubber and miscellaneous plastic products, leather and leather products, stone, clay and glass products; primary metal industries (including blast furnace and basic steel mills, rolling mills, die-casting, and metal heat treating), fabricated metal products, industrial machinery and equipment (including computer equipment), electronic and other electric equipment, transportation equipment, instruments and related products, and miscellaneous manufacturing industries.

• Finance (including Insurance and Real Estate)
  Number employed in finance, insurance and real estate. Examples of businesses the Census classifies in this category are depository institutions (including commercial banks and savings institutions, credit unions, nondepository institutions (personal and business credit institutions, mortgage bankers and brokers), security and commodity brokers, insurance carriers, real estate (including real estate oeprators and lessors, real estate agents and managers, title abstract offices, subdividers and developers), holding and other investment offices (including trusts, investment offices).

• Wholesale Trade
  Number employed in wholesale trade. Examples of businesses the Census classifies in this category are wholesale trade in durable goods (including motor vehicles and parts, furniture and homefurnishings, lumber and construction materials, office equipment, electrical goods, hardware, jewelry and precious stones, scrap and waste materials), wholesale trade in nondurable goods (including paper and paper products, apparel and notions, footwear, groceries and related products, livestock, chemicals, bulk petroleum).

• Transportation (including Public Utilities)
  Number employed in transportation (including public utilities). Examples of businesses the Census classifies in this category are local and interurban passenger transit (bus service, taxicabs, local bus charter and bus terminal and service facilities), trucking and warehousing, water transportation (including ferries, water transport of freight, marine cargo handling, towing and tugboat services, marinas), transportation by air (including air transportation, scheduled and unscheduled, airports, flying fields and services), pipelines, transportation services (including travel agencies, tour operators, freight transportation arrangements), communication (including telephone communication, radio and television broadcasting, cable and other pay TV services), electric, gas, and sanitary services (including electric services, gas production and distribution, water supply, sanitary services, steam and air-conditioning supply, irrigation systems).

• Contract Construction
  Number employed in contract construction. Examples of businesses the Census classifies in this category are general contractors and operative building, heavy construction (including highway, street), special trade contractors (including plumbing, heating, air-conditioning, plainting, electrical work, masonry, plastering, carpentry, roofing, concrete work, water well drilling, structural steel erection, glass and glazing work, excavation work, wrecking and demolition work, installing building equipment).