Census 2000 TIGER/Line(R) Files Technical Documentation Glossary ACF See Address Control File. Address Control File A computer data base developed for the 1990 census by the U.S. Census Bureau to control enumeration in areas with house number-street name style addresses. See also Master Address File. Address List Review Program See Local Update of Census Addresses (LUCA). AIANA See American Indian area, Alaska Native area, Hawaiian home land. AIANA/HHL See American Indian area, Alaska Native area, Hawaiian home land. AIR See American Indian reservation. Alaska Native Regional Corporation (ANRC) A corporate entity organized to conduct both business and nonprofit affairs for Alaska Natives pursuant to the Alaska Native Claims Settlement Act of 1972 (Public Law 92-203). Twelve ANRCs are geographic entities that cover most of the state of Alaska (the Annette Islands Reserve, an American Indian reservation, is excluded from any ANRC). A thirteenth ANRC represents Alaska Natives who do not live in Alaska and do not identify with any of the 12 corporations. The U.S. Census Bureau does not provide data for this ANRC because it has no geographic extent. ANRC boundaries have been legally established. The U.S. Census Bureau offers representatives of the 12 non- profit ANRCs the opportunity to review and update the ANRC boundaries. The U.S. Census Bureau first provided data for ANRCs for the 1990 census. Alaska Native village (ANV) A type of local governmental unit found in Alaska that constitutes an association, band, clan, community, group, tribe, or village recognized pursuant to the Alaska Native Claims Settlement Act of 1972, Public Law 92-203. See also Alaska Native village statistical area. Alaska Native village statistical area (ANVSA) A census statistical entity that represents the densely settled portion of an Alaska Native village (ANV) as delineated for the U.S. Census Bureau by officials of the ANV (or officials of the Alaska Native Regional Corporation (ANRC) in which the ANV is located if not ANV official chose to participate in the delineation process). Because ANVs do not have boundaries that are easily locatable, the U.S. Census Bureau established ANVSAs for the purpose of presenting decennial census data. The U.S. Census Bureau first provided data for ANVSAs for the 1990 census. See also Alaska Native village. American Indian area, Alaska Native area, and Hawaiian home land (AIANA/HHL) A U.S. Census Bureau term referring to these entity types: American Indian reservation, American Indian off-reservation trust land, tribal subdivision, Oklahoma tribal statistical area, state designated American Indian statistical area, Alaska Native Regional Corporation, Alaska Native village, Alaska Native village statistical area, and Hawaiian home land. American Indian reservation-Federal (federal AIR) An area that has been set aside by the United States for the use of tribes, the exterior boundaries of which are more particularly defined in the final tribal treaties, agreements, Executive Orders, federal statutes, Secretarial Orders, and/or judicial determinations. The U.S. Census Bureau recognizes federal reservations as territory over which American Indian tribes have primary governmental authority. These entities are known as colonies, communities, pueblos, rancherias, ranches, reservations, reserves, tribal towns, and tribal villages. The Bureau of Indian Affairs maintains a list of federally recognized tribal governments. The U.S. Census Bureau contacts representatives of American Indian tribal governments to identify the boundaries for federal reservations. The U.S. Census Bureau contacts the Bureau of Indian Affairs (BIA) or other federal agencies if a tribal government cannot supply the boundaries and/or supporting legal documentation for a boundary change. Federal reservations may cross state, county, county subdivision, and place boundaries. The BIA supplied the U.S. Census Bureau with the names and exterior boundaries of the federal AIRs used for the 1990 census. The U.S. Census Bureau first reported data for American Indian reservations in the 1970 census. American Indian reservation-State (state AIR) Some state governments have established reservations for tribes recognized by the state. A governor- appointed state liaison provides the names and boundaries for state recognized American Indian reservations to the U.S. Census Bureau. American Indian tribal subdivision Administrative subdivisions of federally recognized American Indian reservations, off-reservation trust land, or Oklahoma tribal statistical areas (OTSAs). Tribal subdivisions are known as areas, chapters, communities, or districts. These entities are internal units of self-government or administration that serve social, cultural, and/or economic purposes for the American Indians on reservations, off- reservation trust land, or OTSAs. The U.S. Census Bureau obtains the boundary and name information for tribal subdivisions from tribal governments. The U.S. Census Bureau first provided data for American Indian tribal subdivisions in 1980 when it identified them as "American Indian subreservation areas." It did not provide data for these entities in conjunction with the 1990 census. American Indian trust land Areas for which the United States holds title in trust for the benefit of a tribe (tribal trust land) or for an individual Indian (individual trust land). Trust lands can be alienated or encumbered only by the owner with the approval of the Secretary of the Interior or his/her authorized representative. Trust lands may be located on or off a reservation. The U.S. Census Bureau recognizes and tabulates data for reservations and off-reservation trust lands because American Indian tribes have primary governmental authority over these lands. Primary tribal governmental authority generally is not attached to tribal lands located off the reservation until the lands are placed in trust. In U.S. Census Bureau data tabulations, off-reservation trust lands always are associated with a specific federally recognized reservation and/or tribal government. A tribal government appointed liaison provides the name and boundaries of their trust lands. The Bureau of Indian Affairs (BIA), an agency in the U.S. Department of the Interior, identified and provided maps of these areas for use by the U.S. Census Bureau for the 1990 census. The U.S. Census Bureau first reported data for off-reservation tribal trust lands in the 1980 census; in 1990, the trust land data included both tribal and individual trust lands. The U.S. Census Bureau does not identify fee land (or land in fee simple status) or restricted fee lands as specific geographic categories and they are not identified in the TIGER/Line files. ANRC See Alaska Native Regional Corporation. ANV See Alaska Native village. ANVSA See Alaska Native village statistical area. BAS See Boundary and Annexation Survey. BG See block group. BIA See Bureau of Indian Affairs. Block See census block. Block boundary See census block boundary. Block group (BG) A cluster of census blocks having the same first digit of their 4-digit identifying number within a census tract. For example, BG 3 includes all blocks within a census tract numbered between 3001 and 3999. See also block number. Block number See census block number. Block numbering area (BNA) An area delineated for the 1990 census by state officials or (lacking state participation) by the U.S. Census Bureau, following U.S. Census Bureau guidelines, for the purpose of grouping and numbering of decennial census blocks for the 1990 census in counties or statistically equivalent entities in which census tracts had not been established. A BNA was equivalent to a census tract in the U.S. Census Bureau's 1990 census geographic hierarchy. All 1990 BNAs were replaced by census tracts for Census 2000. See also census tract. BNA See block numbering area. Borough In Alaska, a type of governmental unit that is a 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, county subdivision, dependent place, incorporated place, and independent place. Boundary and Annexation Survey (BAS) A U.S. Census Bureau survey of a specified universe of counties (and legally equivalent entities), minor civil divisions (MCDs), incorporated places, American Indian reservations, off- reservation trust lands, and tribal subdivisions. 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, incorporated places, American Indian reservations, off-reservation trust lands, and tribal subdivisions as of January 1 of the year of the survey. The survey also collects specific information on the legal actions that affect 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. CENID Census File Identification Code. The CENID is a U.S. Census Bureau alphanumeric identifier used to uniquely number the GT-polygons within its TIGER partitions. Since the TIGER partitions may include only a portion of a county, a TIGER/Line file may contain multiple CENIDs. Census area The statistical equivalent of a county in Alaska. Census areas are delineated cooperatively by the state of Alaska and the U.S. 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 block The smallest entity for which the U.S. Census Bureau collects and tabulates decennial census information; bounded on all sides by visible and nonvisible features shown on U.S. Census Bureau maps. See also collection block, tabulation block. Census block boundary A census 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. Census block number A four-digit number that identifies a specific block on Census 2000 products. Census 2000 block numbers are not repeated within census tract. In 1990 census blocks had a three-digit number and may have had a one- or two-letter alphabetic suffix. See also collection block number. Census county division (CCD) A statistical subdivision of a county, established cooperatively by the U.S. Census Bureau and state and local officials, for the presentation of decennial census data in 21 states where MCDs have not been legally established, where MCDs do not serve a legal or administrative governmental purpose, and/or where MCDs are not well known, have poorly defined boundaries, and/or have frequent boundary changes. A CCD boundary normally follows visible features and county lines and in most cases coincides with census tract boundaries. See also county subdivision, minor civil division. Census designated place (CDP) A statistical entity, defined for each decennial census 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 local officials and the U.S. Census Bureau, following U.S. Census Bureau guidelines. CDP boundaries usually coincide with visible features or the boundary of an adjacent incorporated place or county line. For Census 2000 there are no population size requirements for CDPs. For the 1990 and previous censuses, the U.S. Census Bureau required CDPs to qualify on the basis of various minimum population size criteria. CDP boundaries may change with changes in the settlement pattern; a CDP with the same name as in a previous census does not necessarily have same boundary. These entities were called unincorporated places for the 1940 through 1970 censuses. See also comunidad. Census feature class code (CFCC) Developed by the U.S. Census Bureau to identify the most prominent characteristics of a feature, the CFCC, as used in the TIGER/Line files, is a three-character code. The first character is a letter describing the feature class; the second and third characters are numbers representing the major and minor categories. Census subarea A statistical subdivision of boroughs, city and boroughs, municipalities, and census areas (county equivalents) in Alaska. Census subareas are delineated cooperatively by the State of Alaska and the U.S. Census Bureau. They were first used in the 1980 census. See also county subdivision. Census tract A small, relatively permanent statistical subdivision of a county delineated for the purpose of presenting decennial census data. The U.S. Census Bureau delineated census tracts in situations where no local participant existed or where local or tribal governments declined to participate. 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 data users established them, census tracts usually contain between 1,500 and 8,000 inhabitants. The spatial size of census tracts varies widely depending on the density of settlement. Census tract boundaries are delineated with the intention of being maintained over a long time so that statistical comparisons can be made from census to census. However, physical changes in street patterns caused by highway construction, new developments, and so forth, may require boundary revisions. Census tracts occasionally are split due to population growth or combined as a result of substantial population decline. They may be split by any subcounty geographic entity. See also census tract number, tribal census tract. 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. Census tract numbers range from 0001 to 9999. Census tract suffixes may range from .00 to .98. For Census 2000, the U.S. Census Bureau reserved the basic census tract numbers 9400 to 9499 for census tracts delineated within or to encompass American Indian reservations or off-reservation trust land that may exist in multiple states or counties. The U.S. Census Bureau uses census tract number 0000 to identify a census tract delineated to provide complete coverage of water area in territorial seas and the Great Lakes. For the 1990 census, the .99 suffix was reserved for census tracts/block numbering areas (BNAs) that contained only crews-of-vessels population; for Census 2000, the crews-of- vessels population is part of the related census tract. Leading zeros are not shown on the U.S. Census Bureau's maps. Central city The largest city of a metropolitan area (MA) or, from the 1950 through 1980 censuses, an urbanized area (UA); also included as central cities are the census designated place (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). See also central place. Central place The core incorporated place(s) or census designated place(s) (CDP) of an urbanized area (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. CFCC See census feature class code. City A type of incorporated place in 49 states and the District of Columbia. In 24 states and the District of Columbia, some or all cities are not part of any minor civil division (MCD), and the U.S. Census Bureau also treats these as county subdivisions, statistically equivalent to MCDs. In four states, Maryland, Missouri, Nevada, and Virginia, some or all cities are not part of any county, and the U.S. Census Bureau also treats these cities as statistically equivalent to a county and county subdivision. See also county subdivision, dependent place, incorporated place, independent city, independent place. City and borough In Alaska, a type of governmental unit that is a primary legal subdivision of the organized portion of the state, similar to a county in other states. Also the incorporated place coextensive with the county equivalent. See also borough, county equivalent. City-style address See house number-street name address. CMSA See consolidated metropolitan statistical area. Collection block A census block that is part of the set of collection geographic areas used in Census 2000 for canvassing and administering the census. See also census block, census block number, and collection block number. Collection block number A four- or five-character number that identifies a specific Census 2000 collection block. Collection block numbers are unique within Census 2000 collection state and county; they are not unique within census tract. See also census block, census block number, and collection block. Collection geography The set of collection geographic areas used for canvassing and administering Census 2000. See also collection block and collection block number. Complete chain A chain (a sequence of non-intersecting line segments) that explicitly references left and right polygons and start and end nodes. The shape points combine with the nodes to form the segments that make a complete chain. Comunidad A census designated place (CDP) in Puerto Rico. Formerly called an aldea in 1980 and earlier censuses. See also census designated place, zonas urbanas. 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. Consolidated city A unit of local government for which the functions of an incorporated place and its county or minor civil division (MCD) have merged. The legal aspects of this action may result in both the primary incorporated place and the county or MCD continuing to exist as legal entities, even though the county or MCD performs few or no governmental functions and has few or no elected officials. Where this occurs, and where one or more other incorporated places in the county or MCD continue to function as separate governments, even though they have been included in the consolidated government, the primary incorporated place is referred to as a "consolidated city." Consolidated metropolitan statistical area (CMSA) A geographic entity defined by the 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, has component parts that are recognized as primary metropolitan statistical areas (PMSAs), and local opinion favors the designation. Whole counties are components of CMSAs outside of New England. In New England the CMSAs are composed of cities and towns. 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. County A type of governmental unit that is the primary legal subdivision of every state except Alaska and Louisiana; also, a type of functioning minor civil division (MCD) found in American Samoa. See also borough, county equivalent, parish. County code A three-digit Federal Information Processing Standards (FIPS) code that identifies each county and statistically equivalent entity within a state. The U.S. Census Bureau assigns the codes within a state based on the alphabetic sequence of county names within that state leaving gaps in the numbering system to accommodate new counties or statistically equivalent entities. See also Federal Information Processing Standard, Geographic Identification Code Scheme. County equivalent A geographic entity that is not legally referred to as a county, but is recognized by the U.S. Census Bureau as equivalent to a county for purposes of data presentation. See also borough, census area, city and borough, independent city, municipality, municipio, parish, state. County subdivision A legal or statistical division of a county recognized by the U.S. Census Bureau for data presentation. See also census county division, city, minor civil division, town, township, unorganized territory. Crews-of-vessels The population on military and merchant ships, but not the inhabitants of houseboats or marinas. In the 1990 census the U.S. Census Bureau showed the crews-of-vessels population in a unique 1990 census tract and block. For Census 2000, crews-of-vessels population is assigned to the land block identified by the U.S. Census Bureau as associated with the homeport of the vessel. The land block will contain a point landmark with a census feature class code (CFCC) of D25. 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. Digital Line Graph (DLG) A computer-readable file, produced by the USGS, of geographic information that covers the same extent as a quadrangle map. DLG See Digital Line Graph. 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 school district, secondary school district, unified district. Entity point A point used for identifying the location of point features (or areal features collapsed to a point), such as towers, places, and so forth. Extended city In 1990, an incorporated place that contained large, sparsely settled area(s) within its legally defined boundaries. That is, one or more areas with a 1990 population density of less than 100 persons per square mile, each of which was at least 5 square miles in extent, which together constituted at least 25 percent of the place's total land area or at least 25 square miles. For the 1990 census, these low-density areas were classified as rural; the remainder of the extended city was classified as urban. See also rural, urban, urban place. FEAT The TIGER/Line file field name for the alternate feature identification code used as a pointer between record types. The FEAT links geographic objects to an alternate or secondary name. Feature See linear feature. Federal Information Processing Standard (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) named populated places, primary county divisions, and other locational entities used to assign codes to places, county subdivisions, and American Indian areas/Alaska Native areas/Hawaiian home lands (AIANA/HHLs)-five digits. FIPS See Federal Information Processing Standard. FIPS code One of a series of codes, issued by the National Institute of Standards and Technology (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 Standard. GBF/DIME-File (Geographic Base File/Dual Independent Map Encoding File) A geographic base file created by the U.S. Census Bureau for the 1970 and 1980 censuses, usually in cooperation with local officials, representing the line segments and related geographic attributes that comprised all or part of the urban cores of metropolitan areas. Created for 80 smaller urban cores for the 1970 census to support the place of work coding operation and expanded to include all urban cores for the 1980 census. 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. Geographic code One or more alphanumeric symbols used to identify a legal or statistical entity. See also Federal Information Processing Standard, GBF/DIME-File. Geographic Identification Code Scheme (GICS) A detailed listing of the geographic codes, associated names, and attributes that the U.S. Census Bureau uses to identify the various legal and statistical geographic entities of the United States in a specific census. See also legal entity, statistical entity. Geographic Information System (GIS) Software that enables the processing and analysis of geographic information on a computer. 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 Geographic Identification Code Scheme. Geometry The part of mathematics dealing with coordinate location and shape. See also geometry and topology, topology. Geometry and Topology These combined characteristics are the logical, mathematical framework upon which geographic objects are manipulated in a GIS. See also geometry, topology. GICS See Geographic Identification Code Scheme. GIS See Geographic Information System. GT See Geometry and Topology. GT-Polygon An area that is an atomic two-dimensional component of one and only one two-dimensional manifold. GT-polygons are elementary polygons that are mutually exclusive and completely exhaust the surface. See also geometry, geometry and topology, topology. Hawaiian home land (HHL) Public land held in trust by the state of Hawaii for the benefit of native Hawaiians; that is, people with at least one half Hawaiian ancestry. Hawaiian home lands have been created pursuant to the Hawaiian Homes Commission Act that the U.S. Congress passed in 1920. Based on a compact between the federal government and the new state of Hawaii in 1959, the Hawaii Admission Act vested land title and responsibility for the program with the state. However, a Hawaiian home land is not a governmental unit; rather, a home land is a tract of land, with a legally defined boundary, that is owned by the state, which, as authorized by the Act, it may lease to one or more native Hawaiians for residential, agricultural, commercial, industrial, pastoral, and any other activities authorized by state law. The U.S. Census Bureau obtains the names and boundaries for Hawaiian home lands from state officials. The names of the home lands are based on the traditional ahupua'a names of the Crown and government lands of the Kingdom of Hawai'i from which the lands were designated, or from the local name for an area. Hawaiian home lands are a new geographic entity for Census 2000. HHL See Hawaiian home land. House number-street name address An address consisting of a structure number and street name; for example, 201 Main St. Incorporated place A type of governmental unit, incorporated under state law as a city, city and borough, municipality (except in the Northern Mariana Islands), 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, independent place. Independent city An incorporated city that is a primary division of a state and legally not part of any county. The U.S. 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 U.S. Census Bureau treats independent places as an MCD equivalent for data tabulation purposes. See also dependent place, incorporated place. Indian reservation See American Indian reservation. Internal point A coordinate value for a point that lies within its geographic area; where possible, the internal point also is a centroid. Island Areas of the United States The Island Areas of the United States are American Samoa, Guam, the Commonwealth of the Northern Mariana Islands (Northern Mariana Islands), and the Virgin Islands of the United States. The U.S. Census Bureau treats the Island Areas as the statistical equivalents of states. Joint use area As applied to any American Indian area/Alaska Native area by the U.S. Census Bureau, an area that is administered jointly and/or claimed by two or more American Indian tribes. The U.S. Census Bureau designates both legal and statistical joint use areas as unique geographic entities for the purpose of presenting statistical data. KGL See key geographic location. Key geographic location (KGL) A KGL represents a special class of address information. It provides a geocoding tool like address ranges, but also identifies a spatial object similar to a landmark. The U.S. Census Bureau uses KGLs to identify named buildings where the use of the feature name enhances the ability to geocode. LAND Landmark Feature Identification Number. A temporary number that uniquely identifies both point and area landmarks within each county file. The LAND is a dynamic number that changes between different versions of the TIGER/Line files. Legal entity A geographic entity whose boundaries, name, origin, and legal/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, incorporated places, American Indian reservations, off-reservation trust land, and Alaska Native Regional Corporations. See also statistical entity. Legislative district An area from which a person is elected to serve in a state legislative body. See also state legislative district, 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. Local update of census addresses (LUCA) A Census 2000 program, established in response to requirements of Public Law 103-430, that provides an opportunity for local and tribal governments to review and update individual address information in the master address file (MAF) and associated geographic information in the TIGER database to improve the completeness and accuracy of both computer files. The governments must sign a confidentiality agreement to participate. Also called the address list review program. LUCA See local update of census addresses. MA See metropolitan area. MAF See master address file. Master Address File (MAF) The U.S. Census Bureau's list of all living quarters nationwide along with their geographic locations. The MAF is maintained through partnerships with the U.S. Postal Service (USPS), with Federal, State, regional, and local agencies, and with the private sector. MCD See minor civil division. Metropolitan area (MA) A collective term, established by the Office of Management and Budget (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. Metropolitan Area code The National Institute of Standards and Technology (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. Metropolitan statistical area (MSA) A geographic entity, defined by the Office of Management and Budget (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 an urbanized area (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. 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, county subdivision, incorporated place, independent place, unorganized territory. Minor civil division (MCD) code A five-digit numeric code assigned by the National Institute of Standards and Technology (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 Standard. MSA See metropolitan statistical area. Municipality In Alaska, a type of governmental unit that is a primary legal subdivision of the organized portion of the state, similar to a county in other states. Also the incorporated place coextensive with the county equivalent. See also borough, county equivalent. Municipality A general term often used to describe incorporated places in all states and minor civil divisions (MCDs) in the New England states. Municipio A type of governmental unit that is the primary legal subdivision of Puerto Rico; the U.S. Census Bureau treats the municipio as the statistical equivalent of a county. NECMA See New England county metropolitan area. Network chains A chain that explicitly references start and end nodes and not left and right polygons. New England county metropolitan area A county based alternative to the city- and town-based New England metropolitan statistical areas (MSAs) and consolidated metropolitan statistical areas (CMSAs). See also consolidated metropolitan statistical area, metropolitan area, metropolitan statistical area, primary metropolitan statistical area. Node A zero-dimensional object that is a topological junction of two or more links or chains, or an end point of a link or chain. Oklahoma tribal statistical area (OTSA) A statistical entity identified and delineated by the U.S. Census Bureau in consultation with federally recognized American Indian tribes that had a former reservation in Oklahoma. The boundary of an OTSA will be that of the former reservation in Oklahoma, except where modified by agreements with neighboring tribes for statistical data presentation purposes. OTSA replaces the 1990 census term tribal jurisdiction statistical area (TJSA). The U.S. Census Bureau first provided data for these former reservations in conjunction with the 1980 census, when it defined a single all-encompassing geographic entity called the "Historic Areas of Oklahoma." OTSA See Oklahoma tribal statistical area. Parish A type of governmental unit that is the primary legal subdivision of Louisiana, similar to a county in other states. Peano key A method of combining coordinates into a single key code composed of alternating longitude and latitude digits and used primarily for nearest point searches. Named for Giuseppe Peano, a 19th century Italian mathematician who proved that two-dimensional space could be considered as a one-dimensional line. PL See Public Law. Place A concentration of population either legally bounded as an incorporated place, or identified by the U.S. Census Bureau as a census designated place (CDP). Incorporated places have legal/statistical descriptions of borough (except in Alaska and New York), city, city and borough, municipality (except in the Northern Mariana Islands), town (except in New England, New York, and Wisconsin), or village. See also census designated place, incorporated place. Place code A five-digit numeric code assigned by the U.S. Geological Society (USGS )to identify populated places, primary county divisions, and other locational entities within a state. The USGS 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 Standard. PMSA See primary metropolitan statistical area. Point See entity point. POLYID Polygon Identification Number. A temporary number assigned to every polygon in the Census TIGER data base. A POLYID is unique only within CENID. Where a TIGER/Line file contains more than one CENID the POLYID may not be unique within that TIGER/Line file. The POLYID is a dynamic number that can change between different versions of the TIGER/Line files. Primary metropolitan statistical area (PMSA) A geographic entity defined by the Federal Office of Management and Budget (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. Public Law Laws of the United States that may be referenced by number, such as PL 94-171 (the 171st law passed by the 94th Congress). Public use microdata area (PUMA) An area with a decennial census population of 100,000 or more people for which the U.S. Census Bureau provides specially selected extracts of raw data from a small sample of long- form census records screened to protect confidentiality. See also public use microdata sample. Public use microdata sample (PUMS) Files containing records, screened to protect confidentiality, representing 5-percent or 1-percent of the housing units in the United States and the persons. Data users can use these files to create their own statistical tabulations and data summaries. See also public use microdata area. PUMA See public use microdata area. PUMS See public use microdata sample. Rural In the 1990 census, the population and territory outside any urbanized area (UA) and the urban part of any place with a 1990 decennial census population of 2,500 or more. See also place, urban, urban place, urbanized area. Rural place In the 1990 census, any incorporated place or census designated place (CDP) located outside a 1990 urbanized area (UA) and having fewer than 2,500 residents in the 1990 decennial census. See also census designated place, incorporated place, urban place. School district The territory administered by the elected or appointed authorities of a state, county, tribal, or other local governmental unit to provide educational services to a resident population. The U.S. Census Bureau provided data tabulations for school districts from the 1970, 1980, and 1990 censuses. See also elementary school district, secondary school district, and unified school district. SDAISA See State designated American Indian statistical area. SDTS See Spatial Data Transfer Standard. 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 school district, school district, unified district. SF See Summary File. Shape point The non-topological points that describe the position and shape of a chain. Shape points exist only where required. Straight lines require no shape points. SLD See State Legislative District. Spatial Data Transfer Standard Released by the National Institute of Standards and Technology (NIST) as FIPS PUB 173, this standard governs the exchange of geographic information between federal agencies. State A type of governmental unit that is the primary legal subdivision of the United States. State code A two-digit Federal Information Processing Standard (FIPS) code assigned by the National Institute of Standards and Technology (NIST) to identify each state and statistically equivalent entity. The NIST assigns the codes based on the alphabetic sequence of state names (Puerto Rico, the U.S. Virgin Islands, and the Pacific Island Areas appear at the end); it documents these codes in a FIPS publication (FIPS PUB 5). Also, a two-digit code assigned by the U.S. Census Bureau to identify each state within its census geographic division (Puerto Rico, the Virgin Islands, and the Pacific Island Territories appear at the end). See also Federal Information Processing Standard, Geographic Identification Code Scheme. State designated American Indian statistical area A statistical entity for state recognized American Indian tribes that do not have a state recognized land base (reservation). SDAISAs are identified and delineated for the U.S. Census Bureau by a designated state official. SDAISAs generally encompass a compact and contiguous area that contains a concentration of individuals who identify with a state recognized American Indian tribe and in which there is structured or organized tribal activity. A SDAISA may not be located in more than one state unless the tribe is recognized by both states, and it may not include area within an American Indian reservation, off-reservation trust land, Alaska Native village statistical area (ANVSA), tribal designated statistical area (TDSA), or Oklahoma tribal statistical area (OTSA). The U.S. Census Bureau established SDAISAs as a new geographic statistical area for Census 2000 to differentiate between state recognized tribes without a land base and federally recognized tribes without a land base. For the 1990 census, all such tribal entities had been identified as TDSAs. State equivalent A type of governmental unit treated by the U.S. Census Bureau as if it were a state for purposes of data presentation. For Census 2000, the state equivalents include the District of Columbia, the Commonwealth of Puerto Rico, the U.S. Virgin Islands, American Samoa, Guam, the Commonwealth of the Northern Mariana Islands, and the U.S. Minor Outlying Islands. See also State. Statistical entity Any specially defined geographic entity or combination of entities, such as a block group, census county division (CCD), census designated place (CDP), census tract, or urbanized area (UA), for which the U.S. Census Bureau tabulates data. Statistical entity boundaries are not legally defined and the entities have no governmental standing. Statistically equivalent entity A type of geographic entity that, for purposes of data tabulation and presentation, the U.S. Census Bureau treats as the counterpart of a similar type of entity; for example, in Alaska a census area is the statistical equivalent of a county. State Legislative District (SLD) Area from which members are elected to state legislatures. The SLDs include the upper (senate) and lower (house) bodies of the state legislature. See also legislative district and voting district. STF See Summary Tape File. Subbarrio Legally defined subdivisions of the minor civil division barrios- pueblo and barrios in 23 municipios in Puerto Rico. See also minor civil division. Sub-MCD See subbarrio. Summary File (SF) One of a series of Census 2000 files containing large amounts of decennial census data for the various levels of the U.S. Census Bureau's geographic hierarchy. See also summary tape file. Summary Tape File (STF) One of a series of 1990 computer files containing large amounts of decennial census data for the various levels of the U.S. Census Bureau's geographic hierarchy. See also summary file. Tabulation block A census block used in Census 2000 data products. See also census block, census block number, and collection block. Tabulation block number A four-character number that identifies a specific Census 2000 tabulation block. Tabulation block numbers are unique within census tract. See also census block, census block number, and collection block. TAZ See Traffic Analysis Zone. TDSA See Tribal Designated Statistical Area. TIGER(R) Topologically Integrated Geographic Encoding and Referencing. TIGER data base A digital (computer-readable) geographic data base that automates the mapping and related geographic activities required to support the U.S. Census Bureau's census and survey programs. TJSA See Tribal Jurisdiction Statistical Area. TLID TIGER/Line Record Identification Number. A permanent identification number that uniquely identifies a complete chain. Topology One component of the science of mathematics dealing with geometric configurations (nodes, complete chains, and polygons) that do not vary when transformed through bending, stretching, or mapping at various scales. Topology explains how points, lines, and areas relate to each other and is used as the foundation for organizing spatial objects in the Census TIGER data base. See also geometry, geometry and topology. Town A type of functioning minor civil division (MCD ) found in the New England States, New York, and Wisconsin; a type of incorporated place in 30 states and the U.S. Virgin Islands. The U.S. Census Bureau treats all towns in New Jersey, Pennsylvania, and South Dakota, and some towns in North Carolina, as the equivalent of an MCD. See also county subdivision, dependent place, incorporated place, independent place. Township (civil or governmental) A type of functioning minor civil division (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 Illinois, Minnesota, and Missouri. (There also are nonfunctioning survey townships in Maine, but these are not recognized by the U.S. Census Bureau for data tabulation purposes.) In states where land was subdivided under the public land survey system, many townships correspond to the survey townships. See also county subdivision, minor civil division. Tract See census tract. Traffic analysis zone (TAZ) A special-purpose geographic entity delineated by state and local transportation officials for tabulating traffic related data from the decennial census, especially journey-to-work and place-of-work statistics. Tribal block group Under the Census 2000 American Indian/Alaska Native area/Hawaiian home land census geographic hierarchy, a cluster of census blocks within a federally recognized American Indian reservation or off- reservation trust land having the same first digit of their 4-digit census block number. Unlike block groups in the standard census geographic hierarchy, tribal block groups can cross state and county boundaries. See also block group. Tribal census tract Under the Census 2000 American Indian/Alaska Native area/Hawaiian home land census geographic hierarchy, a census tract within a federally recognized American Indian reservation or off-reservation trust land. Tribal census tracts are delineated by tribal governments, or the U.S. Census Bureau where a tribal government declined to participate, for the purpose of presenting decennial census data. Usually containing between 1,000 and 8,000 inhabitants, tribal census tracts generally have boundaries that follow visible features. Unlike census tracts in the standard census geographic hierarchy, tribal census tracts can cross state and county boundaries. See also census tract. Tribal designated statistical area (TDSA) A statistical entity identified and delineated for the U.S. Census Bureau by federally recognized American Indian tribes that do not currently have a legally established land base (reservation or off-reservation trust land). A TDSA encompasses a compact and contiguous area that contains a concentration of individuals who identify with a federally recognized American Indian tribe and in which there is structured or organized tribal activity. A TDSA may be located in more than one state, but it may not include area within an American Indian reservation, off-reservation trust land, Alaska Native village statistical area (ANVSA), or Oklahoma tribal statistical area (OTSA). The U.S. Census Bureau first reported data for TDSAs in conjunction with the 1990 census, when both federally and state recognized tribes could identify and delineate TDSAs. For Census 2000, TDSAs now apply only to federally recognized tribes. State recognized tribes without a land base, including those that were TDSAs in 1990, are identified as state designated American Indian statistical areas (SDAISAs), a new geographic entity for Census 2000. See also state designated American Indian statistical area, tribal jurisdiction statistical area. Tribal jurisdiction statistical area (TJSA) A statistical entity identified and delineated for the 1990 census to provide a geographic frame of reference for the presentation of statistical data. 1990 TJSA boundaries were required to follow census block boundaries and were based upon the boundaries of the former reservations of federally recognized tribes in Oklahoma. TJSAs replaced the Historic Areas of Oklahoma recognized by the U.S. Census Bureau for the 1980 decennial census. The 1990 descriptive designation, TJSA, has been changed for Census 2000 to Oklahoma tribal statistical areas (OTSAs). See also Oklahoma tribal statistical areas, tribal designated statistical area. Tribal Subdivision See American Indian tribal subdivision. Trust Land See American Indian trust land. UA See urbanized area. UGA See urban growth area. Unified district A school district inclusive of kindergarten through twelfth grade. See also school district. Unincorporated place See census designated place. United States Geological Survey (USGS) The USGS is a bureau of the U.S. Department of the Interior, and 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, the U.S. Virgin Islands, and the Pacific Island Areas. Unorganized territory (UT) The statistical equivalent of a minor civil division (MCD) encompassing contiguous area that is not within any legally established MCD or incorporated place. The U.S. Census Bureau identifies UTs in ten states. Urban All population and territory within the boundaries of 1990 urbanized areas (UAs) and the urban portion of places outside of UAs that have a 1990 decennial census population of 2,500 or more. See also rural, urban place, urbanized area. Urban Area A collective term used for Census 2000 to refer to all geographic entities classified as urban by the U.S. Census Bureau. See also rural, urban, urbanized area. Urban growth area (UGA) A legally defined entity in Oregon that the U.S. Census Bureau includes in the Census TIGER data base in agreement with the state. UGAs, which are defined around incorporated places, are used to control urban growth and limit urban sprawl. UGA boundaries, which need not follow visible features, are delineated cooperatively by state and local officials and then confirmed in state law. UGAs are a new geographic entity for Census 2000. Urban place Any place with a 1990 decennial census population of 2,500 or more, whether incorporated or census designated (a CDP), and any place regardless of population located within a 1990 urbanized area (UA). Some urban places (extended cities) contain territory that is not designated as urban. See also place, rural place, urbanized area. Urbanized area (UA) For the 1990 census, 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 U.S. Census Bureau uses published criteria to determine the qualification and boundaries of UAs. See also urban, urban place. Urbanized area (UA) code A four-digit numeric code assigned by the U.S. Census Bureau to identify 1990 urbanized areas(UAs). See also Federal Information Processing Standards, Geographic Identification Code Scheme. 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 U.S. Census Bureau treats all villages in New Jersey, South Dakota, and Wisconsin, and some villages in Ohio, as the equivalent of a minor civil division (MCD). Voting district (VTD) Any of a variety of geographic entities, such as precincts, wards, and election districts established by state and local governments for the purpose of conducting elections. The 1990 census term voting district replaced the 1980 term election precinct. VTD See Voting district. ZCTA(TM) See ZIP Code Tabulation Area. ZIP Code Tabulation Area (ZCTA) Approximate area representations of U.S. Postal Service ZIP Code service areas created by the U.S. Census Bureau for statistical purposes. ZIP (Zone Improvement Plan) Code A five-, seven-, nine-, or eleven-digit code assigned by the U.S. Postal Service (USPS) 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 A census designated place (CDP) delineated to represent the governmental center of each municipio in Puerto Rico. See also census designated place, comunidad.