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.

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.

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 ofan 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.

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.

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.

BG See block group.

BIA See Bureau of Indian Affairs.

Block See census block.

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.

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.

CCD See census county division.

CD See congressional district.

CDP See census designated place.

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.

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, 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 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 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.

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.

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.

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.

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.

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.

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.

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 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 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

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.

CSA See census subarea.

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

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.

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).

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.

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.

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.

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 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 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.

GICS See Geographic Identification Code Scheme.

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.

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.

Indian reservation See American Indian reservation.

Individual trust lands See American Indian trust land.

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.

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.

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.

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.

MCD See minor civil division.

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 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, 19 83. 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.

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.

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.

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.

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.

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

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.

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

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.

PMSA See primary metropolitan statistical area.

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

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.

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, standa rd metropolitan area, standard metropolitan statistical 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.

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

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.

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 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.

SCA See standard consolidated area.

SCSA See standard consolidated statistical area.

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.

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 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.

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.

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.

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 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.

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.

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

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.

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.

USGS See United States Geological Survey.

USPS See United States Postal Service.

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.

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.