The Census Bureau used somewhat different procedures to develop the MAF for areas believed to have predominantly city-style mailing addresses (house number and street) than for areas believed to have predominantly rural route and post office box mailing addresses (see Box A-1). City-style areas were those inside the “blue line,” and non-city-style areas were those outside the “blue line.”³ For areas inside the blue line, the Bureau expected to have U.S. Postal Service carriers deliver questionnaires to most addresses on the list; for areas outside the blue line, the Bureau expected to use its own field workers to deliver questionnaires.

For remote rural areas, which have less than 1 percent of the population, Census Bureau enumerators developed the address list concurrently with enumerating households in person. For special places in which people live in nonresidential settings, such as college dormitories, prisons, nursing homes and other group quarters, the Bureau used a variety of sources to develop an address list. About 2.8 percent of the population was enumerated in group quarters in 2000 (tabulations of Census Bureau data); the comparable 1990 figure is 2.7 percent (U.S. Census Bureau, 1996:68).

As the starting point for the MAF for city-style areas inside the blue line, the Census Bureau took the 1990 census address list for these areas and updated it from the Delivery Sequence File (DSF) of the Postal Service. The DSF contains a listing of addresses to which mail is delivered, ordered by carrier routes. It is updated regularly. Legislation passed in 1994 allows the Postal Service to share the DSF with the Bureau.

Although not part of its original plan, the Bureau determined that a complete field check of the city-style list should be conducted, which was done in a block canvass operation for all mailout/mailback areas conducted in January-May 1999. The Bureau also provided an opportunity for local review in 1998–1999 (see “Local Review,” below). Approximately 101 million addresses were included in the MAF for areas inside the blue line at the time when questionnaires were labeled and prepared for mailing in July 1999. The Postal Service conducted an intensive check of the DSF in early 2000, and updates were made to the MAF based on that check prior to questionnaire delivery.

To develop the MAF for non-city-style areas, the Bureau first conducted a block canvass operation, called address listing, in July 1998-February 1999.