Geographic Areas Reference Manual/Glossary

by the U.S. Census Bureau

Glossary

ACG See Address Coding Guide.

Active governmental unit A governmental unit that has elected or appointed officials, raises revenues, and performs governmental activities (such as enactment of laws, provision of services, and entering into contracts). See also functional status (governmental), functioning governmental unit, inactive governmental unit, nonfunctioning governmental unit.

Address The number or other designation assigned to a housing unit, business establishment, or other structure for purposes of mail delivery, emergency services, and so forth. See also city-style address, general delivery address, post office box address, rural address.

Address coding guide (ACG) A computerized inventory of street names, address ranges, and census block numbers, created by the Census Bureau in cooperation with local agencies, to permit the automated assignment of addresses on a mailing list to the geographic entity codes for the 145 largest urban cores of metropolitan areas (MAs) at the time of the 1970 census. Each file contained the name of each block side that was a street or road, its associated address range and ZIP Code, and 1970 census geographic entity information for that side of the street. It was the forerunner of the GBF/DIME-Files and the TIGER data base. See also GBF/DIME-File, TIGER data base.

Address Reference File (ARF) A series of computerized files containing street and building records used to geocode the economic censuses. The files show, by ZIP Code, the low and high addresses associated with each street name within incorporated places of 2,500 or more population, special economic urban areas (SEUAs) of 10,000 or more population, balances of counties, and balances of (S)MSAs.

Address register area (ARA) A geographic entity established by the Census Bureau for 1990 census data collection purposes. It usually consists of a census tract or block group. See also enumeration district, tape address register.

Adjacent A term descriptive of geographic entities that are next to each other and share all or a portion of a common boundary. See also conjoint, contiguous, jump, jump corridor, merger.

Administrative entity A geographic area, usually with legally defined boundaries but often without elected officials, created to administer elections and other governmental functions. Administrative areas include school districts, voting districts, ZIP Codes, and nonfunctioning MCDs such as election precincts, election districts, and assessment districts. See also governmental unit, legal entity, minor civil division, statistical entity.

Agriculture (census) See census of agriculture.

AIANA See American Indian and Alaska Native area.

AIANA code A four-digit number assigned by the Census Bureau to identify AIANAs for data processing and tabulation during the 1990 census; AIANA codes range from 0001 through 4989. A five-digit FIPS code used to identify each AIANA (or portion of an AIANA) within a State. See also Geographic Identification Code Scheme, Federal Information Processing Standards.

Alaska Native For decennial census purposes, includes people who report their race as Aleut or Eskimo as well as those who report race entries such as Alutiiq, Egegik, Pribilovian, Arctic Slope, Inupiat, and Yupik.

Alaska Native Claims Settlement Act (ANCSA) Legislation enacted in 1972 establishing 13 ANRCs to conduct business and nonprofit activities by and for Alaska Natives. See also Alaska Native Regional Corporation, Alaska Native village, Alaska Native village statistical area.

Alaska Native Regional Corporation (ANRC) A corporate entity established by the ANCSA. Twelve ANRCs have specific boundaries that together cover the State of Alaska except for the Annette Islands Reserve (an American Indian reservation). A thirteenth corporation represents Alaska Natives not resident in Alaska who do not identify with any of the other 12 corporations. See also Alaska Native Claims Settlement Act, Alaska Native village, Alaska Native village statistical area.

Alaska Native village (ANV) A type of local governmental unit found in Alaska, with boundaries identified for the Census Bureau by an appropriate authority, that constitutes an association, band, clan, community, group, tribe, or village recognized pursuant to the ANCSA. The Census Bureau tabulated statistical data for ANVs for the 1980 census. ANVs do not have legally defined boundaries. See also Alaska Native Claims Settlement Act, Alaska Native village statistical area.

Alaska Native village statistical area (ANVSA) A 1990 census statistical entity that represents the densely settled extent of an ANV as delineated for the Census Bureau by officials of the ANRC in which the ANVSA is located, or by other appropriate officials, for the purpose of presenting decennial census data. See also Alaska Native Regional Corporation, Alaska Native village.

Aldea A closely settled population center delineated by Puerto Rico officials as the equivalent of a CDP for decennial censuses before 1990. The term was replaced by comunidad for the 1990 census. See also census designated place, comunidad.

American Indian A person who identifies herself or himself as being in the racial classification of an American Indian for decennial census purposes.

American Indian and Alaska Native area (AIANA) A Census Bureau term referring to these entity types: American Indian reservation, American Indian subreservation area, American Indian trust land, tribal jurisdictional statistical area, tribal designated statistical area, Alaska Native Regional Corporation, Alaska Native village, and Alaska Native village statistical area.

American Indian reservation An American Indian entity with boundaries established by treaty, statute, and/or executive or court order. Federal and individual State governments have established reservations as territory over which American Indians have governmental jurisdiction. These entities are designated as colonies, communities, pueblos, rancherias, reservations, and reserves. The Federally recognized reservations, their names, and their boundaries are identified for the Census Bureau by the Bureau of Indian Affairs (BIA), an agency in the U.S. Department of the Interior; State governments identify the names and boundaries of State reservations.

American Indian subreservation area An administrative subdivision of an American Indian reservation, known as an area, chapter, community, district, or segment. These entities are internal units of self-government or administration that serve social, cultural, and/or economic purposes for the American Indians on the reservation. Subreservation areas may lie wholly or partially within an American Indian reservation; a few are located entirely outside any reservation (off-reservation). Tribal governments identified and delineated subreservation areas for the Census Bureau for the 1980 decennial census, the only census in which the Census Bureau has tabulated data for these areas.

American Indian trust land Land held in trust by the Federal government for either a tribe (tribal trust land) or an individual member of that tribe (individual trust land). Such land always is associated with a specific Federally recognized reservation or tribe, but may be located on or off the reservation. The Census Bureau recognizes and tabulates data separately only for off-reservation trust lands. The BIA identifies and provides maps of these areas for use by the Census Bureau.

Analysis unit (AU) A small geographic area consisting of one or more contiguous census blocks, created by the Census Bureau to evaluate their land area and population density and to determine if they should be included in a UA area or extended city. See also extended city, urbanized area.

ANCSA See Alaska Native Claims Settlement Act.

Annex To add territory to a governmental unit, usually an incorporated place, by an ordinance, a court order, or other legal action. See also detach.

Annexation The act or process of adding land to a governmental unit, usually an incorporated place, by an ordinance, a court order, or other legal action.

ANRC See Alaska Native Regional Corporation.

ANV See Alaska Native village.

ANVSA See Alaska Native village statistical area.

ARA See address register area.

Area measurement The determination of the extent of surface area, expressed in square miles and/or square kilometers, of land and/or water within a predetermined boundary. Formerly accomplished by measuring on a correctly scaled map, area measurements for the 1990 census were calculated by computer based on the locations of features and boundaries in the TIGER data base.

Assessment district A nonfunctioning MCD defined only to administer tax assessments for a county. For the 1990 census, the Census Bureau recognized assessment districts as MCDs only in Anne Arundel County, Maryland.

AU See analysis unit.

Barrio A nonfunctioning legal subdivision of a municipio in Puerto Rico, treated as an MCD by the Census Bureau. A barrio (or group of barrios) is the area from which municipio officials and the Commonwealth legislature are elected. See also barrio-pueblo, ciudad, county subdivision, nonfunctioning government.

Barrio-pueblo A nonfunctioning legal subdivision of a municipio in Puerto Rico, treated as an MCD by the Census Bureau. The barrio-pueblo replaces the pueblo reported in decennial censuses prior to 1990. The barrio-pueblo is differentiated from other barrios because it is the historical center and seat of government of its municipio. See also barrio, county subdivision, pueblo.

BAS See Boundary and Annexation Survey.

Beat The former term for a supervisor’s district (MCD) in Mississippi; an MCD in Alabama before the establishment of CCDs. See also minor civil division, supervisor’s district.

BG See block group.

BIA See Bureau of Indian Affairs.

Block See census block.

Block boundary A census map feature, visible or nonvisible, that delimits a census block. Usually, it takes two or more features to delimit a census block, but a single feature may delimit a census block in the case of an island or a circumferential street.

Block group (BG) A combination of census blocks that is a subdivision of a census tract or BNA. A BG consists of all blocks whose numbers begin with the same digit in a given census tract or BNA; for example, BG 3 within a census tract or BNA includes all blocks numbered between 301 and 399. The BG is the lowest level of geography for which the Census Bureau has tabulated sample data in the 1990 census; it was used to tabulate sample data in the 1970 and 1980 censuses only for those areas that had block numbers. See also block number, enumeration district, sample data.

Block number A three-digit number, which may have a one- or two-letter alphabetic suffix for the 1990 census, that identifies a specific census block on census maps and Summary Tape Files (STFs). Block numbers are not repeated within a census tract or BNA.

Block numbering area (BNA) An area delineated by State officials or (lacking State participation) by the Census Bureau, following Census Bureau guidelines, for the purpose of grouping and numbering decennial census blocks in counties or statistically equivalent entities in which census tracts have not been established. A BNA is equivalent to a census tract in the Census Bureau’s geographic hierarchy. See also block numbering area number, census tract.

Block numbering area (BNA) number A four-digit number, possibly with a two-digit suffix, used to identify a BNA within a county. BNA numbers range from 9501 to 9989.

Block side The section of a feature drawn on a Census Bureau map that has a single name and defines one boundary of a census block; for example, one side of Main Street from First Street to Second Street.

BNA See block numbering area.

Borough In Alaska, the type of governmental unit that is the primary legal subdivision of the organized portion of the State, similar to a county in other States. In New York, a functioning MCD; the boroughs are the five entities, one for each county, that together constitute New York city. In Connecticut, New Jersey, and Pennsylvania, an incorporated place; in New Jersey and Pennsylvania, also a county subdivision. See also census area, census subarea, county subdivision, dependent place, incorporated place, independent place, unorganized borough.

Boundary A line, which may or may not follow a visible feature, that defines the limits of a geographic entity such as a block, BNA, census tract, county, or place. See also nonvisible feature, visible feature.

Boundary and Annexation Survey (BAS) A Census Bureau survey of a specified universe of counties (and legally equivalent entities), MCDs, and incorporated places. The purpose of the BAS is to determine the inventory of legally defined entities and the correct names, political descriptions, and legal boundaries of counties, MCDs, and incorporated places as of January 1 of the year of the survey. The survey also collects specific information on the legal actions that effect boundary changes.

Bureau of Indian Affairs (BIA) The Federal Government agency, located in the Department of the Interior, responsible for the historic and legal relationships between the Federal Government and American Indian communities.

CBD See central business district.

CCD See census county division.

CD See congressional district.

CDP See census designated place.

CD-ROM See compact disc—read-only memory.

Census A complete enumeration, usually of a population, but also businesses and commercial establishments, farms, governments, and so forth. See also census of agriculture, census of governments, decennial census, economic census, sample, survey.

Census area The statistical equivalent of a county in Alaska. Census areas are delineated cooperatively by the State of Alaska and the Census Bureau for statistical purposes in the portion of Alaska not within an organized borough; they were used first in the 1980 census. See also borough, census subarea, unorganized borough.

Census block The smallest entity for which the Census Bureau collects and tabulates decennial census information; bounded on all sides by visible and nonvisible features shown on Census Bureau maps. See also collection block, 100-percent data, tabulation block.

Census county division (CCD) A statistical subdivision of a county, established cooperatively by the Census Bureau and State and local government authorities, for the presentation of decennial census data in 21 States that do not have well-defined MCDs; that is, where MCDs have not been legally established, do not serve a legal or administrative governmental purpose, are not well known, have poorly defined boundaries, and/or have frequent boundary changes. A CCD boundary normally follows visible features and county lines, but may follow corporate boundaries and other nonvisible features in selected instances. See also census subarea, county subdivision, minor civil division.

Census designated place (CDP) A statistical entity, defined for each decennial census according to Census Bureau guidelines, comprising a densely settled concentration of population that is not within an incorporated place, but is locally identified by a name. CDPs are delineated cooperatively by State and local officials and the Census Bureau, following Census Bureau guidelines. These entities were called unincorporated places for the 1940 through 1970 censuses. See also aldea, comunidad, whole-town CDP, zona urbana.

Census division See division (census geographic).

Census geography A collective term referring to the geographic entities used by the Census Bureau in its data collection and tabulation operations, including their structure, designations, and relationships to one another.

Census map Any map produced by the Census Bureau that displays the geographic entities used in a Census Bureau census or survey.

Census of agriculture An enumeration of the Nation’s farms, farm population, and agricultural production, conducted by the Census Bureau every five years, in years ending in 2 and 7. See also economic census.

Census of governments An enumeration of all general-purpose governmental units such as States, counties, municipalities, towns and townships, plus limited-purpose local governments (school district governments and special district governments such as housing authorities, and bridge and toll facilities). The Census Bureau conducts the census of governments every five years, in years ending in 2 and 7.

Census region See region (census geographic).

Census statistical areas committee (CSAC) A committee established by local officials and other interested individuals to identify, in cooperation with the Census Bureau, the census tracts, CDPs, and other statistical entities for a county. Referred to as a census tract committee until 1973. See also census statistical areas key person.

Census statistical areas key person (CSAKP) A person designated by the CSAC to act as its contact person with the Census Bureau. Referred to as a census tract key person until 1973. See also census statistical areas committee.

Census subarea (CSA) A statistical division of a borough or census area in Alaska, equivalent to a CCD in other States. Census subareas are delineated cooperatively by officials from Alaska and the Census Bureau. See also borough, census area, census county division.

Census subdistrict A nonfunctioning MCD equivalent in the Virgin Islands of the United States. Census subdistricts were legally defined by the Virgin Islands legislature for the 1980 census.

Census tract A small, relatively permanent statistical subdivision of a county in a metropolitan area (MA) or a selected nonmetropolitan county, delineated by a local committee of census data users (a CSAC) for the purpose of presenting decennial census data. Census tract boundaries normally follow visible features, but may follow governmental unit boundaries and other nonvisible features in some instances; they always nest within counties. Designed to be relatively homogeneous units with respect to population characteristics, economic status, and living conditions at the time the CSAC established them, census tracts usually contain between 2,500 and 8,000 inhabitants. They may be split by any subcounty geographic entity. See also block numbering area, census statistical areas committee, census tract number, central business district.

Census tract committee See census statistical areas committee.

Census tract key person (CTKP) See census statistical areas key person.

Census Tract Manual A Census Bureau publication that described the steps a local census tract committee had to follow when it developed a census tract plan. The first edition was published in 1934; the last, in 1966. See also census statistical areas committee, Geographic Areas Reference Manual.

Census tract number A four-digit number, possibly with a two-digit suffix, used to identify a census tract. Census tract numbers are always unique within a county and usually unique within an MA. Almost all census tract numbers range from 0001 to 9499. Leading zeros are not shown on the Census Bureau’s maps or in its printed reports.

Census Tract/Block Numbering Area Outline Map A map (or set of maps) depicting the boundaries and numbers of census tracts/BNAs in a county or equivalent entity. The map also displays features and feature names underlying the boundaries, and the boundaries and names of counties, AIANAs, county subdivisions, and places (but not the street pattern within census tracts/BNAs). Each map sheet is approximately three feet by four feet in size.

Central business district (CBD) The commercial center of an MA central city or other MA city with a population of 50,000 or more, recognized for tabulating statistical data in the 1948 through 1982 economic censuses, and in the 1950 to 1980 decennial censuses. A CBD was defined as an area of very high land valuation and high traffic flow, characterized by a high concentration of retail and service businesses. CBDs usually consisted of one or more whole census tracts; in the few cases where a CBD tract extended beyond the city limits, the Census Bureau recognized only that part of the census tract within the city as the CBD (or part of the CBD). See also major retail center.

Central city The largest city of an MA or, from the 1950 through 1980 censuses, an urbanized area (UA). (Also included as central cities are the CDP of Honolulu in Hawaii, highly urban MCDs in Massachusetts and New Jersey, and several zonas urbanas in Puerto Rico.) Central cities are a basis for establishment of an MA, and prior to the 1990 census, a UA. Additional cities that meet specific criteria also are identified as central city(ies). In a number of instances, only part of a city qualifies as central, because another part of the city extends beyond the MA boundary. See also central place.

Central place The core incorporated place(s) or CDP(s) of a UA, usually consisting of the most populous place(s) in the UA. If a central place also is defined as an extended city, only the portion of the central place contained within the UA is recognized as the central place. The term was first used for the 1990 census to recognize a CDP as the most populous place in a UA. See also central city, extended city.

Centroid The central location within a specified geographic area. A centroid may fall outside its geographic area, or may be adjusted so that it is located within its geographic area. See also internal point.

Chapter (American Indian) See American Indian subreservation area.

City A type of incorporated place in 49 States and the District of Columbia. In 20 States, some or all cities are not part of any MCD, and the Census Bureau also treats these as county subdivisions, statistically equivalent to MCDs. See also county subdivision, dependent place, incorporated place, independent place.

City Reference File A file from the Economic and Agriculture Census that links the ZIP Codes and post office name information to the geographic entities and their associated codes used in that census (MAs, counties, and places, including incorporated places with more than 2,500 people, and selected MCDs referred to as special economic urban areas, or SEUAs).

City-style address An address consisting of a structure number and street name; for example, 201 Main St. See also address, general delivery address, post office box address, rural address.

Ciudad A term used by the government of Puerto Rico before the 1990 census to refer to a group of barrios (if they contained at least 50,000 people) that identified the municipio’s center of government. See also barrio.

Civil township A type of MCD with a functioning government. See also county subdivision, functioning government, minor civil division.

CMSA See consolidated metropolitan statistical area.

Code The alphanumeric characters assigned to identify a geographic entity (geocode) or a class of population, industries, and occupations, for ease in computer processing, such as a county code, an industry code, an occupational code, a place size code, or an income level; to assign data on a questionnaire to one or more classes of some sort, the entities of which are identified through the use of codes. See also Federal Information Processing Standards, geocode, geographic code, geographic hierarchy, Geographic Identification Code Scheme.

Coextensive Descriptive of two or more geographic entities that cover the same area, with their boundaries coincident.

Coextensive place A place that covers exactly the same area and has the same boundaries as its county subdivision or county.

Coincident Descriptive of two or more features or boundaries that are physically in the same location; for example, a census tract boundary that also serves as a CCD boundary. Also, the common boundary of adjacent entities. See also adjacent, conjoint, contiguous.

Collection block For the 1990 census, a physical block, identified by a unique three-digit number, that was enumerated as a single geographic area regardless of any legal or statistical boundaries that passed through it. See also census block, collection geography, tabulation block, tabulation geography.

Collection geography The geographic entities used by the Census Bureau to take a census. In the 1980 census, this was district office/enumeration district/block; for 1990, district office/address register area/collection block.

Colony (American Indian) A type of American Indian reservation.

Commonwealth The legal designation for four States (Kentucky, Massachusetts, Pennsylvania, and Virginia) and two of the Outlying Areas (Puerto Rico and the Northern Mariana Islands). The Census Bureau does not use this term in presenting census data.

Community (American Indian) A type of American Indian reservation. See also American Indian subreservation area.

Compact disc—read-only memory (CD-ROM) A type of high-density optical or laser disc for use on small computers. One 4¾-inch CD-ROM can hold the contents of approximately 500 printed reports, 1,600 flexible diskettes, or 3 or 4 high-density computer tapes.

Comunidad A CDP in Puerto Rico for the 1990 census; formerly called an aldea. See also aldea, census designated place.

Congressional district (CD) An area established by State officials or the courts for the purpose of electing a person to the U.S. House of Representatives. Within each State, these areas must contain, as nearly as possible, an equal number of inhabitants. The number of CDs in each State may change after each decennial census, and the boundaries may be changed more than once during a decade. See also reapportionment, redistricting.

Congressional township See public land survey system, township (congressional or survey), township and range system.

Conjoint Descriptive of the boundaries for two or more geographic entities or governmental units for which governmental and administrative functions are carried out jointly; descriptive of a boundary shared by two adjacent geographic areas. See also adjacent, consolidated city, consolidated government, consolidation, contiguous, merger.

Consolidated city An incorporated place that has combined its governmental functions with a county or subcounty entity but contains one or more other incorporated places that continue to function as local governments within the consolidated government. See also consolidated government, consolidation, merger.

Consolidated government A governmental unit that comprises two or more legal entities that have joined together to form a common government; for example, a consolidated city-county government. The combined governmental units may or may not occupy the same territory. See also consolidated city, consolidation, merger.

Consolidated metropolitan statistical area (CMSA) A geographic entity defined by the Federal Office of Management and Budget (OMB) for use by Federal statistical agencies. An area becomes a CMSA if it meets the requirements to qualify as a metropolitan statistical area (MSA), has a population of 1,000,000 or more, if component parts are recognized as primary metropolitan statistical areas (PMSAs), and local opinion favors the designation. Whole counties are components of CMSAs outside of New England, where they are composed of cities and towns instead. See also metropolitan area, metropolitan statistical area, primary metropolitan statistical area, standard consolidated area, standard consolidated statistical area, standard metropolitan area, standard metropolitan statistical area.

Consolidation A combination of two or more governmental units. The units may be at the same or different levels of government. See also consolidated city, consolidated government, merger.

Construction (census) See economic census.

Conterminous States The coterminous 48 States and the District of Columbia; that is, the United States excluding Alaska and Hawaii.

Contiguous Descriptive of geographic areas that are adjacent to one another, sharing either a common boundary or point. See also adjacent, conjoint.

Contract block area An area for which a local government paid the Census Bureau to collect and publish decennial census data at the block level because the area was not included automatically in the block-numbering program for a decennial census. This kind of area did not exist for the 1990 census, because the Census Bureau automatically collected and published census block-level data nationwide. See also census block, free block area.

Corporate corridor A narrow strip of land, generally consisting of all or part of the right-of-way of a road, proposed road, power line, or similar feature, that is part of an incorporated place; a corridor also may exist without relation to any accompanying visible feature.

Coterminous A term descriptive of geographic entities that are contiguous with one another and are contained within the same boundaries; for example, the coterminous 48 States and the District of Columbia. See also conterminous States.

County A type of governmental unit that is the primary legal subdivision of every State except Alaska and Louisiana; also, a type of functioning MCD found in American Samoa. See also borough, county equivalent, parish.

County Block Map A set of large-scale maps for each county or equivalent entity, displaying boundaries and names/numbers of census blocks, decennial census tabulation entities, and ground features such as roads and streams. These maps are the most detailed and complete set of cartographic information that the Census Bureau provides.

County code A three-digit code assigned by the National Institute of Standards and Technology (NIST) to identify each county and statistically equivalent entity within a State. The NIST assigns the codes based on the alphabetic sequence of county names; it documents these codes in a FIPS publication (FIPS PUB 6). The Census Bureau also documents these codes in its Geographic Identification Code Scheme. The NIST leaves gaps in the numbering system to accommodate new counties or statistically equivalent entities. See also Federal Information Processing Standards, Geographic Identification Code Scheme.

County equivalent A geographic entity that is not legally referred to as a county, but is recognized by the Census Bureau as equivalent to a county for purposes of data presentation. See also borough, census area, district, independent city, island, municipality, municipio, parish, State.

County group An area with a population of 100,000 or more, generally comprising a group of contiguous counties, identified on one of the 1980 or 1990 census public-use microdata samples (PUMS). The term is applied loosely, since some of the areas included are single counties, single cities, groups of places, or groups of towns or townships in New England and a few other States, all of which meet the 100,000 minimum population criterion. See also public-use microdata area, public-use microdata sample.

County subdivision A legal or statistical division of a county recognized by the Census Bureau for data presentation. See also barrio, barrio-pueblo, census county division, census subarea, census subdistrict, city, gore, grant, island, location, minor civil division, municipality, plantation, purchase, town, township, unorganized territory, village.

County Subdivision Outline Map A State-based map depicting the boundaries and names of the counties and equivalent entities, county subdivisions, AIANAs, and places for which the Census Bureau tabulated 1990 census data. These maps are issued as electrostatic plots consisting of only one or a few map sheets for each State; they also are available in smaller scale, sectionalized form in census publications.

Crews of vessels The shipboard populations of U.S. Navy, U.S. Coast Guard, and merchant marine vessels. For a decennial census, they are assigned to the offshore area adjacent to the land area that contains the facility, pier, or dock associated with the ship; this location is assigned a unique census tract or BNA number, with a suffix of .99, and a unique block number of either 199 (for a military vessel) or 299 (for a civilian vessel). This area is more conceptual than geographic, and has no area measurement assigned to it.

CRF See City Reference File.

CSA See census subarea.

CSAC See census statistical areas committee.

CSAKP See census statistical areas key person.

CTKP See census tract key person.

Cultural feature Any type of artificial feature, such as a street, power line, or fence. See also feature, natural feature, visible feature.

Data base (census geographic) See TIGER data base.

Decennial census The census of population and housing, taken by the Census Bureau in years ending in 0 (zero). Article I of the Constitution requires that a census be taken every ten years for the purpose of reapportioning the U.S. House of Representatives. The first census of population occurred in 1790; the census of housing has been conducted since 1940. See also reapportionment, redistricting.

Delineate To draw or identify on a map the specific location of a boundary.

Dependent place An incorporated place or CDP that is legally or statistically part of the county(ies) and/or county subdivision(s) within which it is located; the statistical data for the place also are tabulated as part of the total for the county(ies) and/or county subdivision(s) that these data are part of. There are three types of dependent places: (1) an incorporated place that is legally part of the county(ies) and/or MCD(s) within which it is located, (2) an incorporated place that is legally part of the county(ies) and statistically part of the county subdivision(s) within which it is located, and (3) a CDP that always is statistically part of the county(ies) and county subdivision(s) within which it is located. See also incorporated place, independent place.

Detach To legally remove an area from a governmental unit, usually an incorporated place, by an ordinance, a court order, or other legal action. Also refers to the act or process of being separated from a governmental unit. See also annex.

Disincorporate To end the legal existence of an incorporated place as an active or inactive governmental unit through legal action by the incorporated place, or a county/State. See also active governmental unit, disorganize, functional status (governmental), functioning governmental unit, inactive governmental unit.

Disorganize To end the legal existence of an MCD as a governmental unit through legal action taken by a county/State. See also disincorporate, functional status (governmental), functioning governmental unit, nonfunctioning governmental unit.

District A type of nonfunctioning county equivalent found in American Samoa; any of several types of geographic areas recognized by the Census Bureau. See also American Indian subreservation area, assessment district, election district, magisterial district, municipal district, Outlying Area, parish governing authority district, road district, voting district.

Division (census geographic) A grouping of States within a census geographic region, established by the Census Bureau for the presentation of census data. The current nine divisions (East North Central, East South Central, Middle Atlantic, Mountain, New England, Pacific, South Atlantic, West North Central, and West South Central) are intended to represent relatively homogeneous areas that are subdivisions of the four census geographic regions. See also region (census geographic).

EC See economic census.

Economic census (EC) Collective name for the censuses of construction, manufactures, minerals, minority- and women-owned businesses, retail trade, service industries, transportation, and wholesale trade, conducted by the Census Bureau every five years, in years ending in 2 and 7. See also census of agriculture, census of governments.

Economic Geographic Information Reference Tape (EGIRT) Before 1992, the control file for geographic codes related to all economic censuses, used for editing the Address Reference File (ARF) and the City Reference File (CRF). The EGIRT contained names and codes for all geographic entities that the Census Bureau recognized in the EC data tabulations.

Economic Geographic Reference File (EGRF) The reference file of geographic entities for the 1992 economic census; replaces the EGIRT used in earlier economic censuses. See also Economic Geographic Information Reference Tape.

Economic subregion (ESR) A combination of two or more State economic areas into a larger, relatively homogeneous geographic unit. The subregions may cross State lines, but are intended to preserve the similar characteristics of the state economic areas used by the Census Bureau to report decennial census data from the 1950 through the 1980 censuses. See also State economic area.

ED See enumeration district.

ED number A one- to four-digit number, in some instances including an alphabetic suffix, that uniquely identified each enumeration district within a district office and county for the 1980 and earlier decennial and special censuses. See also enumeration district.

EGIRT See Economic Geographic Information Reference Tape.

EGRF See Economic Geographic Reference File.

Election district A nonfunctioning class of MCDs in Guam and Maryland.

Election precinct (EP) A nonfunctioning class of MCDs in Illinois and Nebraska that represent a voting area. In the 1980 census, the term used by the Census Bureau for a voting district. See also precinct, voting district.

Elementary school district A school district inclusive of kindergarten through either the eighth or ninth grade or the first through either the eighth or the ninth grade. For the data tabulations from the 1980 and 1990 decennial censuses, this term includes both elementary and intermediate/middle districts. See also independent district, intermediate/middle district, school district, secondary district.

Enclave An island of area with one set of geographic codes within and completely surrounded by an area with a different set of geographic codes; usually refers to unincorporated area that is completely surrounded by an incorporated place.

Enumeration district (ED) A small geographic entity established by the Census Bureau as a basic unit for data collection and tabulation in a decennial or special census before 1990. (For the 1970 and 1980 censuses it was superseded by the BG as the lowest level for which the Census Bureau tabulated sample data in those areas that had block numbers assigned.) An ED usually consisted of the area to be assigned to an individual enumerator for canvassing. All area included in a single ED was in the same governmental unit(s) or statistical area(s). The ED was replaced by the address register area (ARA) for data collection purposes in the 1990 census; it also was totally replaced by the BG as the lowest level of geography for which the Census Bureau tabulated sample data. See also address register area, block group, ED number, sample data.

EP See election precinct.

ESR See economic subregion.

Exclave A discontiguous part of a geographic entity; also referred to as an outlier. Usually refers to a small portion of an incorporated place that is completely separate from the remainder of the place.

Extended city An incorporated place that contains large, sparsely settled area(s) within its legally defined boundaries; that is, one or more areas with a population density of less than 100 persons per square mile, each of which is at least 5 square miles in extent, which together constitute at least 25 percent of the place’s total land area or at least 25 square miles. These low-density areas are classified as rural; the remainder of the extended city is classified as urban. Before the 1990 census, the Census Bureau identified extended cities only within urbanized areas.

Feature Any part of the landscape, whether natural (such as a stream or ridge) or artifical (such as a road or power line). In a geographic context, features are any part of the landscape portrayed on a map, including legal entity boundaries such as city limits or county lines. See also cultural feature, nonvisible feature, visible feature.

Feature extension The imaginary straight-line extension from the end of a map feature, usually a street or road, to another feature; for example, from the end of a dead-end street to a nearby river.

Federal Information Processing Standards (FIPS) Any of the standardized systems of numeric and/or alphabetic coding issued by the National Institute of Standards and Technology (NIST), an agency in the U. S. Department of Commerce, for use by the Federal Government and others. Several series of FIPS identify standard geographic codes for States, counties, metropolitan areas, congressional districts, foreign geographic entities, and named populated and related locational entities. Geographic elements to be assigned codes are first alphabetized and then assigned codes serially, generally with systematic gaps that permit additions to the list. The basic geographic code formats published in FIPS publications (FIPS PUBs) are (1) States—two digits, (2) counties and county equivalents—three digits, (3) metropolitan areas—four digits; CMSAs and the former SCSAs also have two-digit codes, (4) congressional districts—two digits, (5) foreign geographic entities—two or three digits, (6) named populated places, primary county divisions, and other locational entities used to assign codes to places, county subdivisions, and AIANAs—five digits. See also FIPS code.

FIPS See Federal Information Processing Standards.

FIPS code One of a series of codes, issued by the NIST, assigned for the purpose of ensuring uniform identification during computer processes involving geographic entities throughout all Federal Government programs and agencies. See also Federal Information Processing Standards.

FIPS PUB See FIPS publication.

FIPS publication (FIPS PUB) One in a series of U.S. Government publications containing a standard set of geocodes for different types of geographic entities. See also Federal Information Processing Standards, FIPS code.

Free block area An area for which the Census Bureau provided block-level data without charge in the 1980 and earlier decennial censuses. See also census block, contract block area.

Functional status (governmental) The administrative or legal activities associated with performing the legally prescribed functions of a governmental unit; that is, the administrative or legal entity is functioning or nonfunctioning, and if functioning, is either active or inactive. See also active governmental unit, functioning governmental unit, governmental unit, inactive governmental unit, nonfunctioning governmental unit.

Functioning governmental unit A general-purpose government that has the legal capacity to elect or appoint officials, raise revenues, provide services, and enter into contracts. See also active governmental unit, functional status (governmental), general-purpose government, governmental unit, inactive governmental unit, nonfunctioning governmental unit.

GARM See Geographic Areas Reference Manual.

GBF See Geographic Base File.

GBF/DIME-File (Geographic Base File/Dual Independent Map Encoding File) A geographic base file created by the Census Bureau, usually in cooperation with local officials, representing the line segments and related geographic attributes that comprised all or part of the urban cores of all metropolitan areas. Created for the 80 smaller urban cores to supplement the ACG coverage for the 1970 census and support the place of work coding operation, this format was expanded to include all urban cores for the 1980 census by converting the ACGs in a program called the ACG Improvement Program. Each file contained the name of each segment of a mapped feature, its associated address range and ZIP Code if applicable, 1980 census geographic area information for both sides of each segment, node numbers that identified feature intersections and selected points of a curved line, and x,y coordinate information for each node in the file. The file contained information describing the street network in the major urban centers, and was used to build the TIGER data base. See also Address Coding Guide, geographic base file, TIGER data base, TIGER System.

General delivery address A type of postal delivery service offered at post offices without carrier delivery service for customers who do not want a post office box, and at any post office to serve transients and customers who are not permanently located. See also address, city-style address, post office box address, rural address.

General-purpose government A functioning governmental unit that, through appointed or elected officials, performs many tasks and provides a wide range of services. See also governmental unit.

Geocode A code assigned to identify a geographic entity; to assign an address (such as housing unit, business, industry, farm) to the full set of geographic code(s) applicable to the location of that address on the surface of the Earth. See also Address Coding Guide, GBF/DIME-File, geographic base file, geographic code, TIGER data base, TIGER System.

Geographic Areas Reference Manual (GARM) A geographic reference source developed by the Census Bureau as a guide for local CSACs and other agencies and groups working with the Census Bureau to maintain and improve the geographic areas, concepts, and methods used for the presentation of decennial and economic census data. See also census statistical areas committees, census tract manual.

Geographic base file (GBF) A generic term for a computer file of geographic attributes of an area (such as street names, address ranges, geographic codes, hydrography, railroads). See also Address Coding Guide, GBF/DIME-File, TIGER data base, TIGER System.

Geographic code One or more alphanumeric symbols used to identify a legal, administrative, or statistical entity. See also Address Coding Guide, Federal Information Processing Standards, GBF/DIME-File, geocode, geographic base file, geographic data base, TIGER data base, TIGER System.

Geographic data base A computer-readable data base, the primary structure of which includes geographic codes and/or coordinates. The GBF/DIME-File and TIGER data base are geographic data bases used by the Census Bureau to conduct the 1980 and 1990 censuses, respectively. See also Address Coding Guide, GBF/DIME-File, TIGER data base, TIGER System.

Geographic entity A geographic unit of any type—legal, administrative, or statistical. See also geographic code, geographic data base, geographic hierarchy.

Geographic hierarchy A system of relationships among geographic entities in which each geographic entity (except the smallest one) is subdivided into lower-order units that in turn may be subdivided further. For example, States are subdivided into counties, which are subdivided into county subdivisions. Most 1990 census reports and STFs present data in all or part of the hierarchical sequence: United States, region, division, State, county, county subdivision, place (incorporated/census designated), place part or remainder of county subdivision, census tract/block numbering area (or part), block group (or part), and block. See also geographic code, geographic data base, part.

Geographic Identification Code Scheme (GICS) A detailed listing of the geographic codes, associated names, and attributes that the Census Bureau used to identify the various legal, administrative, and statistical geographic entities of the United States in a specific census. See also administrative entity, legal entity, statistical entity.

Geographic reference file (GRF) A generic term for a file that contains geographic information such as area names, geographic codes, and selected x,y coordinate values (entity centroid or internal point). Geographic reference files may be used for determining the name of a particular geographic entity when only its code is known (or vice versa), and for control of geographic operations, computer mapping, and entity name placement, depending on the information contained in the specific file. See also Economic Geographic Information Reference Tape, Economic Geographic Reference File, Geographic Identification Code Scheme, Geographic Reference File (Codes), Geographic Reference File (Names).

Geographic Reference File (Codes) (GRF-C) A Census Bureau computer file listing all geographic codes associated with a census block record.

Geographic Reference File (Names) (GRF-N) A Census Bureau computer file listing the names of each geographic entity and their associated attributes.

Geographic Support System (GSS) The TIGER System, plus all other activities undertaken by the Geography division to support the census and survey activities of the Census Bureau. This includes all decennial census geographic products—maps, TIGER/Line files™, other TIGER extract products, and related computer systems; all economic and agriculture censuses geographic products—the Address Reference File (ARF), City Reference File (CRF), Economic Geographic Reference File (EGRF), and related computer systems. Also includes geographic activities related to the Master Address File (MAF), the special census program, the current sample survey program, all future census research and development activities, the operations that use the boundary change information collected in the BAS, the U.S. Geological Survey (USGS) quadrangles and other reference/map source files, and the congressional district referral service. See also TIGER data base, TIGER System.

GICS See Geographic Identification Code Scheme.

Gore A type of nonfunctioning MCD found in Maine and Vermont.

Governmental unit A geographic entity established by legal action, and for the purpose of implementing administrative or governmental functions. Most governmental units have officially recognized boundaries. All area and population of the United States are part of one or more legal units, such as American Indian reservations, States, counties, county subdivisions, and incorporated places. See also active governmental unit, administrative entity, functioning governmental unit, general-purpose government, inactive governmental unit, legal entity, nonfunctioning governmental unit.

Governments, (census) See census of governments.

Grant A type of nonfunctioning MCD in New Hampshire and Vermont.

GRF See Geographic Reference File.

GRF-C See Geographic Reference File (Codes).

GRF-N See Geographic Reference File (Names).

Group quarters A place where unrelated people live, such as a barracks, a boarding house, a dormitory, a hospital, or a prison. Group quarters are not typical housing units such as apartments, townhouses, and single family homes.

GSS See Geographic Support System.

Hierarchy (census geographic) See geographic hierarchy.

Historic Areas of Oklahoma The area of the former American Indian reservations that had legally established boundaries during the period 1900 through 1907 but were dissolved during the two- to three-year period preceding the establishment of Oklahoma as a State in 1907. The Historic Areas boundaries were delineated for the Census Bureau by the BIA and excluded all territory in urbanized areas. They were used for tabulating data from the 1980 census. The Census Bureau did not retain the Historic Areas for the 1990 census. See also tribal jurisdiction statistical area.

Inactive governmental unit A governmental unit that is not exercising its legal capacity to have elected or appointed officials; thus, it neither raises revenue nor provides services. An inactive governmental unit is not classified as a government by the Census Bureau. See also active governmental unit, functional status (governmental), functioning governmental unit, governmental unit, nonfunctioning governmental unit.

Incorporated place A type of governmental unit, incorporated under State law as a city, town (except in New England, New York, and Wisconsin), borough (except in Alaska and New York), or village, having legally prescribed limits, powers, and functions. See also dependent place, governmental unit, independent place.

Independent city An incorporated city that is a primary division of a State and legally not part of any county. The Census Bureau treats an independent city as both a county equivalent and MCD equivalent for data tabulation purposes. See also incorporated place.

Independent place An incorporated place that legally is not part of any MCD. The Census Bureau treats independent places as a primary division of a county and an MCD equivalent for data tabulation purposes. See also dependent place, incorporated place.

Independent school district A type of public school system that is administratively and fiscally independent of any other governmental unit. (By contrast, a dependent public school system is an agency of some other government—State, county, municipal, or township.) The census of governments collects and tabulates data for both kinds of school districts.

Indian reservation See American Indian reservation.

Individual trust lands See American Indian trust land.

Intermediate/middle school district A school district inclusive of the fifth through eighth grade, the sixth through the ninth grade, the seventh and eighth grades, or the seventh through ninth grade. The Census Bureau did not provide a separate identification of intermediate/middle school districts in its 1990 census tabulations. See also elementary district, independent district, school district, secondary district.

Internal point A coordinate value for a point that lies within its geographic area; where possible, the internal point also is a centroid. See also centroid.

Island An area of land totally surrounded by water; a type of nonfunctioning county equivalent in American Samoa and the Virgin Islands of the United States; a type of nonfunctioning MCD equivalent in American Samoa.

Joint use area (American Indian) Territory that is administered jointly and/or claimed by two or more American Indian tribes.

Jump The process by which the Census Bureau includes qualifying territory (that is, territory with a population density of at least 1,000 people per square mile) in an urbanized area (UA) when that territory is not adjacent to the main body of the UA. The non-adjacent qualifying territory must be connected to the main body of the UA either by roads or other transportation arteries; these arteries may be no more than 1.5 miles in combined length over developable land, or no more than 5 miles in combined length over water or undevelopable territory. See also adjacent, jump corridor, population density, undevelopable land, urbanized area.

Jump corridor Territory forming a corridor along the transportation artery(ies) connecting non-adjacent qualifying territory to the main body of an urbanized area (UA). For the 1990 census, the jump corridor, together with the qualifying territory that was not adjacent to the main body of the UA, had to have a population density of at least 500 people per square mile. See also adjacent, jump, population density, urbanized area.

Legal entity A geographic entity whose boundaries, name, origin, and political/statistical area description result from charters, laws, treaties, or other administrative or governmental action. In earlier censuses, often referred to as a political area or entity. Legal entities include States, counties, minor civil divisions, American Indian reservations, and Alaska Native Regional Corporations. See also administrative entity, governmental unit, political/statistical area description, statistical entity.

Legislative district An area from which a person is elected to serve in a State legislative body. See also voting district.

Linear feature A feature, such as a railroad, road, street, stream, pipeline, or boundary that can be represented by a line in a geographic data base. See also TIGER data base, visible feature.

Location A type of nonfunctioning MCD found in New Hampshire.

Long form The decennial census questionnaire, sent to approximately one in six households for the 1980 and 1990 censuses, that contains, in addition to all questions on the short form, detailed questions relating to the social, economic, and housing characteristics of each individual and household. Information derived from the long form is referred to as sample data, and is tabulated for geographic entities as small as the block group level in 1980 and 1990 census data products. See also block group, 100-percent data, sample data, short form.

MA See metropolitan area.

MA code The NIST issues numeric FIPS codes for MAs. FIPS codes for MSAs and PMSAs (and NECMAs) are four-digit codes; CMSAs are assigned two-digit FIPS codes. NIST also has made available an alternative set of four-digit codes for CMSAs. See also Federal Information Processing Standards, Geographic Identification Code Scheme.

MAF See Master Address File.

Magisterial district A type of nonfunctioning MCD found in Virginia and West Virginia.

Major retail center (MRC) A cluster of retail stores outside the CBD containing at least one general merchandise store, with a specified minimum dollar amount in annual sales or a specified minimum amount of floor space. Defined and used by the Census Bureau for the Censuses of Retail Trade from 1954 through 1982. See also central business district.

Manufactures (census) See economic census.

Master Address File (MAF) The Census Bureau’s permanent list of addresses for individual living quarters that is linked to the TIGER data base and will be continuously maintained through partnerships with the USPS, with Federal, State, regional, and local agencies, and with the private sector. (The MAF will eventually include addresses for business establishments.)

MCD See minor civil division.

Merger The joining of two or more geographic entities, generally governmental units, but also MAs or UAs, into a single geographic entity. See also annexation, conjoint, consolidated city, consolidated government, consolidation.

Metropolitan area (MA) A collective term, established by the Federal OMB and used for the first time in 1990, to refer to metropolitan statistical areas (MSAs), consolidated metropolitan statistical areas (CMSAs), and primary metropolitan statistical areas (PMSAs). In addition, there is an alternative set of areas termed NECMAs. See also metropolitan districts.

Metropolitan Areas Map A large-scale color map showing the boundaries and names of all MSAs, CMSAs, and PMSAs in the United States and Puerto Rico as of June 30, 1993. The MAs are displayed in four different population size categories; also shown are the extent of UAs and the location of State and county boundaries. Formatted in wall size (46 inches by 30 inches), this map is Number 4 in the Census Bureau’s GE-90 Map Series.

Metropolitan district A statistical area comprising a central city and adjacent incorporated places, densely settled MCDs, and, in some cases, EDs. It was used in the 1910, 1920, 1930, and 1940 decennial censuses, and was the forerunner of the MA and the UA.

Metropolitan planning organization (MPO) A local governmental unit that has legal jurisdiction over a geographic area for government service planning such as transportation and land-use planning.

Metropolitan statistical area (MSA) A geographic entity, defined by the Federal OMB for use by Federal statistical agencies, based on the concept of a core area with a large population nucleus, plus adjacent communities having a high degree of economic and social integration with that core. Qualification of an MSA requires the presence of a city with 50,000 or more inhabitants, or the presence of a UA and a total population of at least 100,000 (75,000 in New England). The county or counties containing the largest city and surrounding densely settled territory are central counties of the MSA. Additional outlying counties qualify to be included in the MSA by meeting certain other criteria of metropolitan character, such as a specified minimum population density or percentage of the population that is urban. MSAs in New England are defined in terms of cities and towns, following rules concerning commuting and population density. MSAs were first defined and effective June 30, 1983. See also consolidated metropolitan statistical area, metropolitan area, metropolitan statistical area, primary metropolitan statistical area, standard consolidated area, standard consolidated statistical area, standard metropolitan area, standard metropolitan statistical area.

Microdata See public-use microdata sample.

Minerals (census) See economic census.

Minor civil division (MCD) A type of governmental unit that is the primary legal subdivision of a county in 28 States, created to govern or administer an area rather than a specific population. The several types of MCDs are identified by a variety of terms, such as town, township, and district, and include both functioning and nonfunctioning governmental units. Many MCDs represent local, general-purpose governmental units, which makes them required areas for presentation of decennial census data. See also census county division, census subarea, county subdivision, incorporated place, independent place, unorganized territory.

Minor civil division (MCD) code A three-digit numeric code assigned by the Census Bureau to identify each MCD within a county (the Census Bureau assigns the codes based on the alphabetical sequence of the MCD names); also, a five-digit numeric code assigned by the NIST to identify populated places, primary county divisions, and other locational entities within a State. The NIST assigns the codes based on the alphabetic sequence of the entity names; it documents these codes in FIPS 55. See also Geographic Identification Coding Scheme, Federal Information Processing Standards.

Minority- and women-owned businesses, (census of) See economic census.

MPO See metropolitan planning organization.

MRC See major retail center.

MSA See metropolitan statistical area.

Municipal district A type of nonfunctioning MCD found in Guam.

Municipality A type of functioning county equivalent found in the Northern Mariana Islands for the 1990 census; a functioning MCD found in the Northern Mariana Islands for the 1980 census and in Palau for the 1990 census; the generic term used for a general-purpose local government, such as an incorporated place or MCD.

Municipio A type of governmental unit that is the primary legal subdivision of Puerto Rico; the Census Bureau treats the municipio as the statistical equivalent of a county.

National Institute of Standards and Technology (NIST) An agency of the U.S. Department of Commerce, the NIST (formerly the National Bureau of Standards) serves as the Nation’s science and engineering laboratory for measurement technology and standards research.

Natural feature Any part of the landscape resulting from natural processes (such as a stream or ridge), in contrast to the activity of man. See also cultural feature, feature, visible feature.

NECMA See New England County Metropolitan Area.

Neighborhood A special-purpose entity delineated for the Census Bureau’s 1980 Neighborhood Statistics Program. Neighborhoods have locally defined boundaries, and the Census Bureau treated them as subareas within a legally defined governmental unit, usually an incorporated place or county.

New England County Metropolitan Area (NECMA) County-based areas defined by the Federal OMB to provide an alternative to the city- and town-based MSAs and CMSAs in New England. A NECMA includes the county containing the first-named place in an MSA/CMSA title (this county may include the first-named places of other MSAs or CMSAs), and each additional county having at least half its population in the MSA(s)/CMSA(s) whose first-named place is in the county identified in the previous step. NECMAs were first defined in 1975. See also consolidated metropolitan statistical area, metropolitan area, metropolitan statistical area.

NIST See National Institute of Standards and Technology.

Nonfunctioning governmental unit A legally defined governmental unit that does not have appointed or elected officials, raise revenues, or perform general purpose governmental activities such as enacting laws, entering into contracts, or providing services. The term usually refers to an entity established to administer a task assigned to another governmental unit. A nonfunctioning governmental unit is not classified as a government by the Census Bureau. See also active governmental unit, administrative entity, functioning governmental unit, functional status (governmental), governmental unit, inactive governmental unit.

Nonmetropolitan The area and population not located in any MA.

Nonphysical feature See nonvisible feature.

Nonresidential urban land use Any type of cultural land use, such as parks, transportation facilities (airports and railyards), factories, and office and industrial parks, that generally are not populated, but are considered to be integral parts of the urban landscape. When calculating the population density of a census block or AU to define a UA or extended city, the Census Bureau disregards the land area occupied by such land uses; the resultant population density figure more accurately reflects the residential density of the census block or AU. See also population density.

Nonstreet feature A map feature that is not a street, but for which records exist on a map or in a geographic base file. Nonstreet features include pipelines, governmental unit boundaries, power lines, railroads, and water features. See also nonvisible feature, visible feature.

Nonvisible feature A map feature that is not visible, such as a city or county boundary, a property line, a short imaginary extension of a street or road, or a point-to-point line. See also visible feature.

OA See Outlying Area.

Off-reservation A subreservation entity, or tribal or individual trust land, that is located entirely outside the boundaries of an American Indian reservation. See also American Indian subreservation area, American Indian trust land.

Office of Management and Budget (OMB) The OMB (formerly the Bureau of the Budget) is that part of the Executive Branch responsible for evaluating, formulating, and coordinating management procedures and program objectives within and among Federal departments and agencies. It also controls the administration of the Federal budget, while routinely providing the President with recommendations regarding budget proposals and relevant legislative enactments.

OMB See Office of Management and Budget.

100-percent data Population and housing information collected from both the long form and the short form for every inhabitant and household in the United States, and tabulated for all geographic levels down to the census block. See also geographic hierarchy, long form, sample data, short form.

Organized territory Any area that lies within an established legal entity, such as a State, county, MCD, or incorporated place. See also unorganized territory.

Outlier See exclave.

Outlying Area An entity, other than a State or the District of Columbia, under the jurisdiction of the United States; for the 1990 census, this included American Samoa, Guam, the Northern Mariana Islands, Palau, Puerto Rico, the Virgin Islands of the United States, and several small islands in the Caribbean Sea and the Pacific Ocean. The Census Bureau treated other entities as outlying areas in earlier censuses. The Census Bureau uses Puerto Rico and the Outlying Areas to refer to these areas as a group.

Parish A type of governmental unit that is the primary legal subdivision of Louisiana, similar to a county in other States.

Parish governing authority district (PGAD) A type of nonfunctioning MCD found in Louisiana used for reporting decennial census data.

Part That portion of a geographic entity contained within some higher-level geographic entity, the boundary of which transects the first entity. See also administrative entity, geographic entity, geographic hierarchy, legal entity, statistical entity.

PGAD See parish governing authority district.

Physical feature See visible feature.

Place A concentration of population either legally bounded as an incorporated place, or identified by the Census Bureau as a CDP. Incorporated places have political/statistical descriptions of borough (except in Alaska and New York), city, town (except in New England, New York, and Wisconsin), or village. See also census designated place, incorporated place, political/statistical area description.

Place code A four-digit code assigned by the Census Bureau to identify each incorporated or census designated place within a State (the Census Bureau assigns the codes based on the alphabetic sequence of the place names). Also, the five-digit numeric code assigned by the NIST to identify populated places, primary county divisions, and other locational entities within a State. The NIST assigns the codes based on the alphabetic sequence of the entity names; it documents the codes in FIPS PUB 55. See also Geographic Identification Code Scheme, Federal Information Processing Standards.

Plantation A type of functioning MCD found in Maine.

PLSS See public land survey system.

PMSA See primary metropolitan statistical area.

Police jury ward A type of nonfunctioning MCD found in Louisiana and used to tabulate data in the 1980 and several earlier decennial censuses; replaced by the parish governing authority district for the 1990 census.

Political entity See administrative entity, governmental unit, legal entity, statistical entity.

Political/statistical area description (PSAD) A two-digit numeric code identifying each type of geographic entity in terms of its legal status or status as a statistical entity. (The Census Bureau established 98 PSADs for use in the 1990 census.) The Census Bureau uses PSADs to tabulate data for geographic entities by type, and, where necessary, to append the type to the entity name in the census data presentations.

Population density A numerical method of expressing the extent to which people are clustered within a specific geographic area, usually in terms of people per square mile or per square kilometer. The population density of an area is derived by dividing the total population of the entity by the total land area of the entity. See also jump, nonresidential urban land use, urban fringe, urbanized area.

Post office box address An address that refers to a box number in a post office building, and not to the actual physical location of a housing unit or business establishment. See also address, city-style address, general delivery address, rural address.

Precinct A legal entity subdividing a county, established by counties or municipalities for administrative or electoral purposes and used by the Census Bureau as an MCD in Illinois and Nebraska; one of several types of small geographic entities created by State and local governments for the purpose of administering elections, and for which the Census Bureau tabulated data in 1980 and 1990 as prescribed by Public Law 94-171. See also administrative entity, election precinct, minor civil division, voting district.

Primary metropolitan statistical area (PMSA) A geographic entity defined by the Federal OMB for use by Federal statistical agencies. If an area meets the requirements to qualify as a metropolitan statistical area (MSA) and has a population of one million or more, two or more PMSAs may be defined within it if statistical criteria are met and local opinion is in favor. A PMSA consists of a large urbanized county, or a cluster of such counties (cities and towns in New England) that have substantial commuting interchange. When one or more PMSAs have been recognized, the balance of the original, larger area becomes an additional PMSA; the larger area of which they are components then is designated a consolidated metropolitan statistical area (CMSA). PMSAs were first defined and effective on June 30, 1983. See also consolidated metropolitan statistical area, metropolitan area, metropolitan statistical area, standard consolidated area, standard consolidated statistical area, standard metropolitan area, standard metropolitan statistical area.

PSAD See political/statistical area description.

Pseudo MCD Refers to the MCD recognized in, and comprising the area of, Arlington County, Virginia; St. Louis, Missouri; other independent cities; and independent places below the county level. Although these entities have no MCDs, it is inappropriate to classify them as unorganized territory. See also county subdivision, independent city, independent place.

Public land survey system (PLSS) The grid system by which units of land in the United States are described in relation to established north-south (township) and east-west (range) base lines. The resultant areas are referred to as congressional townships, survey townships, or townships, and generally are six-square-mile units. Townships, in turn, may be subdivided into one-square-mile units, called sections, which also may be subdivided further. Because of the spherical shape of the earth and irregularities in the original surveys, occasional corrections, which appear on maps as jogs or offsets, are introduced along specific township and range lines. See also minor civil division, survey township, township (civil or governmental), township (congressional or survey), township and range system.

Public-use microdata area (PUMA) An area that defines the extent of territory for which the Census Bureau tabulates PUMS data. See also public use microdata samples.

Public-use microdata samples (PUMS) Computerized files consisting of the actual responses provided by individuals about themselves and their housing units rather than summary or tabulated statistics for geographic areas. To maintain confidentiality, the PUMS files contain no names, addresses, or other information that would permit identification of an individual person or housing unit. Users can manipulate these files to prepare tabulations of their own design. See also public-use microdata area.

Pueblo A type of American Indian reservation; before the 1990 census, the term used for the legal subdivision, or MCD equivalent, of a municipio (the county equivalent) in Puerto Rico. The term barrio-pueblo replaced pueblo for the 1990 census. See also barrio-pueblo.

PUMA See public-use microdata area.

PUMS See public-use microdata samples.

Purchase A type of nonfunctioning MCD found in New Hampshire.

Rancheria (American Indian) A type of American Indian reservation.

Range See public land survey system, township and range system.

Reapportionment The redistribution of seats in the U.S. House of Representatives among the several States on the basis of the most recent decennial census, as required under Article I of the Constitution. See also decennial census, redistricting.

Redistricting The delineation of representational district boundaries, based on the most recent decennial census, for the purpose of electing representatives to a State legislature, the U.S. House of Representatives, or a county or city council. See also decennial census, election district, election precinct, precinct, reapportionment, voting district.

Region (census geographic) Four groupings of States (Northeast, South, Midwest, and West) established by the Census Bureau in 1942 for the presentation of census data. Each region is subdivided into divisions. See also division (census geographic).

Reservation A type of functioning MCD equivalent found in Maine and New York, consisting of an American Indian reservation recognized by the Federal government or a State government; the reservation is independent of any other MCD. See also American Indian reservation.

Reserve (American Indian) A type of American Indian reservation.

Retail trade (census) See economic censuses.

Road district A type of functioning MCD found in Potter County, Pennsylvania, originally established to maintain roads, that has become a general-purpose government.

Rural The population and territory outside any UA and the urban part of any place with a decennial census population of 2,500 or more. See also extended city, place, urban, urban area, urban place, urbanized area.

Rural address An address consisting of a delivery route number and a box number, both assigned by the local post office for delivery of mail at a specific physical location. RR (rural route) is the most frequent route designation; also possible are HC (highway contract), RD (rural delivery), RFD (rural free delivery). See also address, city-style address, general delivery address, post office address.

Rural place Any incorporated place or CDP located outside a UA and having fewer than 2,500 residents in the most recent decennial census. See also census designated place, incorporated place, urban place.

SAC See Statistical Areas Committee.

Sample A statistical subset of the total population, used to estimate information about the population; to statistically select a subset of the total population, for the purpose of estimating information about that population. See also census, sample data, survey.

Sample data Detailed social, economic, and housing information collected on the decennial census long form from approximately one in six households nationwide. The Census Bureau tabulated sample data from the 1980 and 1990 decennial census to the block group level. See also decennial census, long form, 100-percent data, short form.

Sample survey The collection of information for a sample of people, housing units, and economic activities. See also census, sample.

SCA See standard consolidated area.

School attendance area A special-purpose geographic entity delineated by State, county, or local officials designating the school(s) that school-age children in that particular area must attend. The Census Bureau does not provide separate data for school attendance areas. See also elementary school district, independent district, intermediate/middle school district, school district, secondary school district, unified school district.

School district The territory administered by the elected or appointed authorities of a State, county, or other local governmental unit to provide educational services to a resident population. A school district typically includes several school buildings, teachers, and related staff. The Census Bureau provided data tabulations for school districts from the 1970, 1980, and 1990 censuses. See also elementary school district, independent district, intermediate/middle school district, secondary school district, unified school district.

SCSA See standard consolidated statistical area.

SEA See State Economic Area.

Secondary school district A school district inclusive of only high school (either the ninth through the twelfth grades or the tenth through the twelfth grades). See also elementary district, independent district, intermediate/middle district, school district, unified school district.

Segment A portion, or subset, of a larger unit, generally in reference to population groups. For the Census Bureau, there are three specific uses of the term: (1) a type of administrative subdivision found on an American Indian reservation; (2) a portion of a linear feature, generally occurring between the intersections with two other linear features, but also between two points used to define the shape of a feature; and (3) the part of a census block (or ED in earlier decennial censuses) used as the sampling unit for the Census Bureau’s sample surveys in areas without city-style addresses geocoded to the census block level. See also American Indian subreservation area, GBF/DIME-File, linear feature, TIGER data base, TIGER System.

Serpentine numbering The method or pattern of assigning numbers on a map in a snake-like, winding manner, with the intent of having each number located next to the other in the sequence.

Service industries (census) See economic census.

Short form The decennial census questionnaire, sent to approximately five of six households for the 1980 and 1990 censuses, that contains population questions related to household relationship, sex, race, age, marital status, and Hispanic origin as well as housing questions about the number of units in each structure, the number of rooms per unit, tenure, and value. The questions contained on the short form also are asked, along with additional questions, on the long form. See also long form, 100-percent data, sample data.

SMA See standard metropolitan area.

Small-area data The Census Bureau uses this term to refer to census statistics tabulated at the census block, block group, and census tract/BNA level. (Many people also would include in this category, data for places and MCDs having fewer than 5,000 inhabitants.)

SMSA See standard metropolitan statistical area.

Special economic urban area (SEUA) A minor civil division in the Northeastern States, Michigan, Minnesota, and Wisconsin treated by the Census Bureau as equivalent to a place for statistical purposes in the economic censuses.

Standard consolidated area (SCA) The SCA was a forerunner of the CMSA. Two SCAs (for the New York and Chicago areas) existed between 1959 and 1975. These SCAs were combinations of SMSAs, although the New York SCA also included two counties that were not within any SMSA. The SCA was replaced by the SCSA. See also consolidated metropolitan statistical area, metropolitan area, metropolitan statistical area, primary metropolitan statistical area, standard consolidated statistical area, standard metropolitan area, standard metropolitan statistical area.

Standard consolidated statistical area (SCSA) The SCSA was a forerunner of the CMSA. An SCSA was a combination of two or more SMSAs that had substantial commuting between them and where at least one of the SMSAs had a population of 1,000,000 or greater. SCSAs were first defined in 1975 and used until June 1983. See also consolidated metropolitan statistical area, metropolitan area, metropolitan statistical area, primary metropolitan statistical area, standard consolidated area, standard metropolitan area, standard metropolitan statistical area.

Standard metropolitan area (SMA) SMA was the first term used for official metropolitan areas as defined by the then Bureau of the Budget. SMAs were first defined in 1949 for the 1950 decennial census, and the term was used until replaced in 1959 with the term SMSA. See also consolidated metropolitan statistical area, metropolitan area, metropolitan statistical area, primary metropolitan statistical area, standard consolidated area, standard consolidated statistical area, standard metropolitan statistical area.

Standard metropolitan statistical area (SMSA) In 1959, the term SMSA replaced SMA for the official metropolitan areas defined by the then Bureau of the Budget. The term SMSA was used until MSAs, CMSAs, and PMSAs were introduced in 1983. See also consolidated metropolitan statistical area, metropolitan area, metropolitan statistical area, primary metropolitan statistical area, standard consolidated area, standard consolidated statistical area, standard metropolitan area.

State/state A type of governmental unit that is the primary legal subdivision of the United States; a functioning county equivalent in Palau, where it also serves as a nonfunctioning MCD.

State certifying official The State official designated annually by the Governor of each State to review and certify that the Census Bureau’s inventory of local governmental units in that State is accurate, and that the boundary change actions reported in response to its BAS are accomplished in accordance with State law.

State code A two-digit FIPS code assigned by the NIST to identify each State and statistically equivalent entity. The NIST assigns the codes based on the alphabetic sequence of State names (Puerto Rico and the Outlying Areas appear at the end); it documents these codes in a FIPS publication (FIPS PUB 5). Also, a two-digit code assigned by the Census Bureau to identify each State within its census geographic division (Puerto Rico and the Outlying Areas appear at the end). See also division (census geographic), Federal Information Processing Standards, Geographic Identification Code Scheme.

State/County Outline Map A page-size, State-based map series depicting the boundaries and names of all counties and equivalent entities in a State.

State economic area (SEA) A group of adjacent counties within a State that have similar economic and social characteristics, as determined by various governmental agencies. An SEA may be a single metropolitan county with unique characteristics. SEAs are the lower level of a two-tiered system of county combinations that includes the economic subregions (ESRs). From 1950 through 1980, the Census Bureau tabulated decennial census data by SEA/ESR. See also economic subregion.

State equivalent A type of governmental unit treated by the Census Bureau as if it were a State for purposes of data presentation. For the 1990 decennial census, the State equivalents included the District of Columbia, the Commonwealth of Puerto Rico, the Virgin Islands of the United States, American Samoa, Guam, the Commonwealth of the Northern Mariana Islands, and Palau. See also Outlying Area, State.

State/Metropolitan Area Outline Map A page-size, State-based map series displaying the boundaries and names of States, counties, and MAs; also shown are the location and name of the State capital, each MA central city, and other places with a population of 25,000 or more in the State.

Statistical Areas Committee (SAC) A committee composed of individuals representing the various divisions and staffs of the Census Bureau. The committee meets as needed to discuss proposals and problems related to the recognition and delineation of geographic entities used for data tabulation.

Statistical entity Any specially defined geographic entity or combination of entities, such as a block group, BNA, CCD, CDP, census tract, or UA, for which the Census Bureau tabulates data. Statistical entity boundaries are not legally defined and the entities have no governmental standing. See also administrative entity, governmental unit, legal entity, statistically equivalent entity.

Statistically equivalent entity A type of geographic entity that, for purposes of data tabulation and presentation, the Census Bureau treats as the counterpart of a similar type of entity; for example, in Louisiana (which has no counties) the parish is the statistical equivalent of a county. See also administrative entity, governmental unit, legal entity, statistical entity.

STF See Summary Tape File.

Subbarrio A legally defined nonfunctioning subdivision of a barrio-pueblo or barrio in Puerto Rico, which serves as an electoral and representational entity. See also barrio, barrio-pueblo, sub-MCD.

Sub-MCD A primary legal division of an MCD, found only in Puerto Rico. See also subbarrio.

Subreservation area (American Indian) See American Indian subreservation area.

Summary Tape File (STF) One of a series of computer files containing large amounts of decennial census data for the various levels of the Census Bureau’s geographic hierarchy. See also 100-percent data, sample data.

Supervisor’s district A nonfunctioning MCD found in Mississippi, used for the election of a member to the county board; in decennial censuses before 1990, the set of EDs for which one supervisor was responsible. The Census Bureau did not tabulate or publish data for supervisor’s districts.

Survey See sample survey.

Survey township See public land survey system, township (congressional or survey), township and range system.

Tabulation block All blocks for which the Census Bureau tabulates decennial census data, either an unsplit census block, or each portion of a decennial census collection block that was split into two or more separately identified parts to recognize any legal, administrative, or statistical boundaries that transect it. For the 1990 census, a tabulation block was identified by a three-digit number and, when it consisted of the portion of a collection block delimited by some other boundary, a one- or two-character alphabetic suffix; earlier decennial censuses did not identify these portions of split blocks with unique suffixes. See also census block, collection block, collection geography, tabulation geography.

Tabulation geography The geographic entities for which the Census Bureau tabulates and presents data, such as States, counties, places, census tracts, and census blocks.

Tape address register (TAR) For the 1970, 1980, and 1990 decennial censuses, a computerized list of residential addresses created from a commercial mailing list and post office check. The extent of this file was restricted to the areas covered by the ACGs (for the 1970 census), the GBF/DIME Files (for the 1980 census), and the TIGER data base (for the 1990 census). The address information was supplemented by field-listed addresses that the lister geocoded because the computer could not geocode them.

TAR See tape address register.

TAZ See traffic analysis zone.

TDSA See tribal designated statistical area.

TIGER The acronym for Topologically Integrated Geographic Encoding and Referencing System. See also TIGER data base, TIGER System.

TIGER data base A computer file that contains geographic information representing the position of roads, rivers, railroads, and other census-required map features; the attributes associated with each feature, such as feature name, address ranges, and class codes; the position of the boundaries for those geographic areas that the Census Bureau uses in its data collection, processing, and tabulation operations; and the attributes associated with those areas, such as their names and codes. This file is stored in multiple partitions, such as by counties or groups of counties, although it represents all U.S. space (including Puerto Rico, and the Outlying Areas) as a single seamless data inventory. See also Geographic Support System, TIGER System.

TIGER File See TIGER data base.

TIGER System The TIGER data base plus the specifications, procedures, computer programs, and related source (input) materials required to build and use it. It also includes the specifications, procedures, and computer programs for using the TIGER data base to perform geocoding, plot maps, and generate tabulation control files such as the GRF. See also Geographic Support System, TIGER data base.

TJSA See tribal jurisdiction statistical area.

Topography In its broadest sense, topography includes landforms, water and other drainage features, and features such as gravel pits and mine tailings. A single feature (such as a mountain or valley) is called a topographic feature.

Topologically Integrated Geographic Encoding and Referencing System See TIGER data base, TIGER System.'

Topology One component of the science of mathematics dealing with geometric configurations that do not vary when transformed through bending, stretching, or mapping at various scales.

Town A type of functioning MCD found in the New England States, New York, and Wisconsin; a type of incorporated place in 30 States and the Virgin Islands of the United States. In New Jersey, Pennsylvania, and South Dakota, the Census Bureau treats these towns as the equivalent of an MCD. See also county subdivision, dependent place, incorporated place, independent place.

Township (civil or governmental) A type of functioning MCD in 12 States, a type of nonfunctioning MCD in 3 States (Arkansas, New Hampshire, and North Carolina), and a type of county subdivision that can be functioning and nonfunctioning in Missouri. (There also are nonfunctioning survey townships in Maine, but these are not recognized by the Census Bureau for data tabulation purposes.) In States where land was subdivided under the PLSS, many townships correspond to the survey townships. See also county subdivision, minor civil division, public land survey system, township (congressional or survey), township and range system.

Township (congressional or survey) A unit of land created under the PLSS for the sale of public lands. A survey township is usually a six-square-mile area consisting of 36 one-square-mile sections aligned along cardinal compass points. Survey townships have not been used for decennial census tabulations in recent decades except where they are organized into a civil township; if unorganized, the area is treated as the statistical equivalent of an MCD, called an unorganized territory. See also organized territory, public land survey system, township (civil or governmental), township and range system, unorganized territory.

Township and range system A common name for the United States Public Land Survey System, which covers 29 whole States and part of Ohio. See also public land survey system, township (civil or governmental), township (congressional or survey).

Traffic analysis zone (TAZ) A special-purpose geographic entity delineated by an MPO for tabulating transportation statistics from the decennial census.

Transportation (census) See economic census.

Tribal designated statistical area (TDSA) A statistical entity delineated for the 1990 decennial census by an American Indian tribe recognized by the Federal Government or a State government when that tribe does not have a land base (reservation). It encompasses the area that includes the American Indian population over which the tribe has jurisdiction. A TDSA cannot overlap with a Federal or State reservation or American Indian trust land; it also cannot cross a State line, and must be delineated following census block boundaries. See also tribal jurisdiction statistical area.

Tribal jurisdiction statistical area (TJSA) A statistical area identified and delineated for the 1990 decennial census by American Indian tribal officials in Oklahoma. They encompass the area that includes the American Indian population over which the tribe has jurisdiction. TJSAs replaced the Historic Areas of Oklahoma recognized by the Census Bureau for the 1980 decennial census. See also Historic Areas of Oklahoma, tribal designated statistical area.

Tribal trust land See American Indian trust land.

UA See urbanized area.

UA code A four-digit numeric code assigned by the Census Bureau to identify UAs. See also Federal Information Processing Standards, Geographic Identification Code Scheme.

Undevelopable territory (urbanized area) Includes water areas, mud flats, swamps, marshlands, steep slopes, and other terrain on which residential or commercial development is virtually impossible because of physical limitations. Local zoning classifications of land do not necessarily correspond to the Census Bureau’s definition of undevelopable land for the purpose of defining UAs. Territory that is undeveloped is not necessarily undevelopable. See also jump, jump corridor, urbanized area.

U.S. See United States.

Unified district A school district inclusive of kindergarten through twelfth grade. See also school district.

Unincorporated place See census designated place.

United States The 50 States and the District of Columbia.

United States Geological Survey (USGS) A bureau of the U.S. Department of the Interior, the USGS is the Nation’s main topographic mapping agency.

United States Postal Service (USPS) An independent corporation of the U.S. Government, the USPS provides mail processing and delivery services to individuals and businesses in the United States, Puerto Rico, and the Outlying Areas.

Unorganized borough A legal entity in Alaska, covering the portion of the State not within any legally established, organized borough; it is administered by the State of Alaska. The unorganized borough is subdivided into county-equivalent census areas for statistical purposes. See also borough, census area.

Unorganized territory (UT) The statistical equivalent of an MCD encompassing contiguous area that is not within any organized MCD or an incorporated place. The Census Bureau identified UTs in nine States for the 1990 census. See also county subdivision, minor civil division, organized territory, statistical entity, township (congressional or survey).

Urban All population and territory within the boundaries of UAs and the urban portion of places outside of UAs that have a decennial census population of 2,500 or more. See also extended city, rural, urban area, urbanized area, whole-town CDP.

Urban area For Census Bureau purposes, the territory within UAs and the urban portion of places outside of UAs that have a decennial census population of 2,500 or more. Other Federal Government agencies may define the term based on different criteria. See also extended city, rural, urban, urbanized area.

Urban fringe The closely settled territory adjacent to the central place(s) of a UA. The census blocks that constitute the urban fringe generally have an overall population density of at least 1,000 people per square mile of land area. See also population density, urbanized area.

Urban place Any place with a decennial census population of 2,500 or more, whether incorporated or census designated (a CDP), and any place regardless of population located within a UA. Some urban places (extended cities) contain territory that is not designated as urban. See also extended city, place, rural place, urbanized area.

Urbanized area (UA) An area consisting of a central place(s) and adjacent urban fringe that together have a minimum residential population of at least 50,000 people and generally an overall population density of at least 1,000 people per square mile of land area. The Census Bureau uses published criteria to determine the qualification and boundaries of UAs. See also central place, jump, jump corridor, nonresidential urban land use, population density, undevelopable territory, urban, urban area, urban fringe.

Urbanized Area Outline Map A small-scale map of each UA, showing the boundaries and names of the major component geographic entities (such as all AIANAs, county subdivisions, and places). Formatted at a scale of four miles to the inch, these maps appear in selected decennial census publications.

USGS See United States Geological Survey.

USPS See United States Postal Service.

UT See unorganized territory.

Village A type of incorporated place in 20 States and American Samoa. The Census Bureau treats all villages in New Jersey, South Dakota, and Wisconsin, and some villages in Ohio as county subdivisions. See also incorporated place, independent place.

Visible feature A feature that can be seen on the ground, such as a street or road, railroad track, power line, stream, shoreline, fence, ridge, or cliff. A visible feature can be a cultural or natural feature. See also cultural feature, feature, nonvisible feature.

Voting district (VTD) Any of a variety of areas, such as election districts, precincts, legislative districts, or wards, established by States and local governments for voting purposes. The 1990 census term voting district replaces the 1980 term election precinct. See also administrative entity, election precinct, precinct.

Voting District Outline Map A county-based map showing VTD names and codes, VTD boundaries and underlying features, boundaries and names of AIANAs, county subdivisions, and places. These maps are available only as electrostatic plots, and cover only those counties for which States delineated VTDs in the 1990 census.

VTD See voting district.

Ward A type of local electoral subdivision of an incorporated place or MCD; a type of MCD formerly recognized by the Census Bureau in Louisiana; officially called a police jury ward. See also voting district.

Wholesale trade (census) See economic census.

Whole-town CDP For the 1980 census only, a CDP coextensive with an MCD in one of the nine Northeastern States, Michigan, or Wisconsin. At least 95 percent of the MCD’s population and 80 percent of its land area had to qualify as urban under the UA criteria. The Census Bureau did not tabulate data for this entity for the 1990 census.

ZIP (Zone Improvement Plan) Code A five-, seven-, nine-, or eleven-digit code assigned by the U.S. Postal Service to a section of a street, a collection of streets, an establishment, structure, or group of post office boxes, for the delivery of mail.

Zona Urbana (ZU) In Puerto Rico, the area consisting of the municipio seat of government and the adjacent built-up area. ZUs are delineated using a process similar to that for comunidades, except that ZUs have no minimum population threshold for qualification and cannot cross municipio boundaries. See also census designated place, comunidad.

Zone Improvement Plan (ZIP) See ZIP Code.

ZU See zona urbana.