Glossary

Table 1. A
Term Definition
address elements The components of a street address, including house number, prefix direction, street name, street type, and postfix direction. These elements are parsed by GeoStan and should not be entered separately.
address geocoding See geocode, geocoding.
address standardization Address standardization is the process of taking an address and verifying that each component meets U.S. Postal Service guidelines for addresses. For example, when properly abbreviated, "123 Main Avenue" appears as "123 Main Ave." During standardization, minor misspellings, dropped address elements, and abbreviations are corrected and the correct city, state, and ZIP Code are provided.
alias A recognized alternate for a street name maintained by association in the database.
alias information Data returned with certain enums when it exists. Not returned by all enums even if specifically requested.
alternate record Additional or differing information that may be available about a specific address but that differs from the base record. See the enums table for necessary flag settings.
Table 2. B
Term Definition
base record The principle, rather than an alternate, record within the database.
block assignments(or blockface) For the assignment of ZIP + 4 codes, one side of a street, from one intersection to the next.
Table 3. C
Term Definition
carrier route The addresses to which a carrier delivers mail. In common usage, a carrier route includes city routes, rural routes, highway contract routes, post office box sections, and general delivery units.
CASS Coding Accuracy Support System. A service offered to mailers, service bureaus, and software vendors that improves the accuracy of delivery point codes, ZIP + 4 codes, 5-digit ZIP Codes, and carrier route information on mail. CASS provides a common platform to measure the quality of address matching software and useful diagnostics to correct software problems.
CBSA A statistical geographic entity consisting of the county or counties associated with at least one core (urbanized area or urban cluster) of at least 10,000 population, plus adjacent counties having a high degree of social and economic integration with the core as measured through commuting ties with the counties containing the core. Metropolitan and Micropolitan Statistical Areas are the two categories of Core Based Statistical Areas.
CBSA Division A subdivision of CBSA.
Census block ID The 15-digit identification number used to specify a particular aggregate or block of addresses associated through census processes.
Census FIPS Code/Census ID See FIPS code.
centroid The calculated center of an area. The coordinates that define a centroid are the average of the sets of coordinates that describe the area.
centroid match An address that has, through geocoding, been found to match a defined geocentroid.
city state key A six-character USPS key that uniquely identifies a city name in the city/state file. Each city has a unique city state key.
CMSA name, CMSA number (Consolidated Metropolitan Statistical Area) The name represents the largest city in a statistical area. The number represents a 4-digit FIPS code.
County The primary legal division of every state except Alaska and Louisiana. A number of geographic entities are not legally designated as a county, but are recognized by the U.S. Census Bureau as equivalent to a county for data presentation purposes. These include the boroughs, city and boroughs, municipality, and census areas in Alaska; parishes in Louisiana; and cities that are independent of any county in Maryland, Missouri, Nevada, and Virginia. They also include the municipios in Puerto Rico, districts and islands in American Samoa, municipalities in the Northern Mariana Islands, and islands in the Virgin Islands of the United States. Because they contain no primary legal divisions, the Census Bureau treats the District of Columbia and Guam each as equivalent to a county (as well as equivalent to a state) for data presentation purposes. In American Samoa, a county is a minor civil division.
coordinates See latitude/longitude coordinates.
CPO Community Post Office. A contract postal unit that provides service in small communities where independent post offices have been discontinued. A CPO bears its community’s name and ZIP Code as part of a recognized address.
CSA A geographic entity consisting of two or more adjacent Core Based Statistical Areas (CBSAs) with employment interchange measures of at least 15. Pairs of CBSAs with employment interchange measures of at least 25 combine automatically. Pairs of CBSAs with employment interchange measures of at least 15, but less than 25, may combine if local opinion in both areas favors combination.
Table 4. D
Term Definition
datum A mathematical model of the Earth used to calculate the coordinates on any map, chart, or survey system. Surveyors take an ellipsoid model of the Earth and fix it to a base point. The North American Datum (NAD) is the official reference ellipsoid used for the primary geodetic network in North America.
directionals A geographic address line component that precedes (predirectional) or follows (postdirectional) the street name.
DPBC The Delivery Point Bar Code is a POSTNET barcode that consists of 62 bars with beginning and ending frame bars and 5 bars each for the 9 digits of the ZIP + 4 code, the last 2 digits of the primary street address number (or post office box, and so on), and a correction digit. The DPBC allows automated sorting of mail to the carrier level in walk sequence.
DPC certified Delivery point code certified. A software or hardware device that meets U.S.P.S. standards for evaluating a properly standardized ZIP + 4 code address and determines the correct 2-digit DPC and checkdigit.
Table 5. E
Term Definition
eLOT The Enhanced Line of Travel(eLOT)Product was developed to provide mailers the ability to sort their mailings in approximate carrier-casing sequence. To aid in mail sorting, eLOT contains an eLOT sequence number field and an ascending/descending code. The eLOT sequence number indicates the first occurrence of delivery made to the add-on range within the carrier route, and the ascending/descending code indicates the approximate delivery order within the sequence number. Mailers can use eLOT processing to qualify for enhanced carrier route presort discounts.
Table 6. F
Term Definition
Finance Area A Finance Area is an area defined by the U.S. Postal Service from which it collects cost and statistical data. A Finance Area is frequently used for area searches, since it covers some or all of the ZIP Code areas in a town or city.
finance number An assigned six-digit number that identifies and installation for processing it’s financial data. The first two digits are the state code and the next four are uniquely assigned from 0001 through 9999 to each installation in alphabetical order.
FIPS code (Federal Information Processing Standards code) A FIPS Code, also called a Census ID, uniquely identifies each piece of Census geography. The syntax of the FIPS code is as follows: ssccctttt.ttgbbb where:ss = the two-digit State Census FIPS Codeccc = the three-digit County Census FIPS Codetttt.tt = the 6-digit Census Tract Census FIPS Codeg = the single-digit Block Group Census FIPS Codebbb = the Block Census FIPS Code.
Table 7. G
Term Definition
GDT (Geographic Data Technology) data produced by TomTom, a premium vendor of street segment files.
geocode, geocoding A geocode is the geographic information associated with a unique address or centroid, such as longitude and latitude. Geocoding is the process of assigning data based upon location information. GeoStan uses an address or ZIP Code to assign latitude, longitude, and Census FIPS information.
GIS (Geographic Information System) A computer-based tool for enhancing geographic data by analyzing both the physical location in space and the set of characteristics associated with a location.
GSD files
GsEnums Enumerated types in the GeoStan API. These enums are prefixed with "GS_" and are defined in the geostan.h file.
GSL file USPS eLOT and Z4Change data. This files is used to assign line of travel (LOT) codes to addresses.
GSU files GSU files contain information to match addresses based on unique ZIP Code and additional highrise unit information.
GSX files (Geographic spatial index) These files are used by spatial functions and reverse geocoding in GeoStan.
GSZ file GeoStan ZIPMove file contains USPS ZIPMove data.
Table 8. H
Term Definition
handle A reference to an object that is required by the Library and is not to be manipulated directly by the developer. The handle is generated when the library is initialized and is required for many library functions.
HERE A premium vendor of street segment and point-level data, formerly known as "NAVTEQ".
Table 9. I
Term Definition
intersection matches Intersections matches are indicated by an x___ match code. For example, 28th Street and Valmont intersections may be standardized and geocoded and return demographic information. Intersections do not represent a valid address for mailings.
Table 10. L
Term Definition
LACS (Locatable Address Conversion System) This system corrects addresses electronically for areas that have undergone permanent address conversions. The address conversion occurred as a result of the 911 system implementation and involves renumbering and renaming rural route and highway contract route information as city-style addresses with street number and name.
lat/lon Coordinates (latitude/longitude coordinates) Longitude and latitude coordinates are always in degrees, and are always represented as 64-bit doubles. Positive numbers represent the Eastern and Northern hemispheres, respectively, and negative numbers represent the Western and Southern hemispheres. For example, the point 140W by 30N would be represented as –140.0,30.0. The library always assumes that the longitude coordinate is the horizontal direction and the latitude coordinate is the vertical direction. Support is not provided for user coordinates.
location code Location codes indicate the accuracy of the assigned geocode.
Table 11. M
Term Definition
mail stop designator This designator indicates a routing code used by a company for internal mail delivery.
MASS (Multiline (OCR) Accuracy Support System) A tool similar to Coding Accuracy Support System (CASS) that accesses and checks the address matching software used by customers’ multiline optical character readers (OCRs).
match code Indicates the portions of the address that matched or did not match with the address information in the GeoStan data files.
match mode The algorithm used by GeoStan to match an input address to an address in the data files.
match rates The number of input addresses that correspond (can be matched) to address information in data files.
MBR (Minimum bounding rectangle) A geographic region defined by and minimum and maximum latitude and longitude.
Metropolitan Statistical Area A Core Based Statistical Area associated with at least one urbanized area that has a population of at least 50,000. The Metropolitan Statistical Area comprises the central county or counties containing the core, plus adjacent outlying counties having a high degree of social and economic integration with the central county as measured through commuting.
Micropolitan Statistical Area A Core Based Statistical Area associated with at least one urban cluster that has a population of at least 10,000, but less than 50,000. The Micropolitan Statistical Area comprises the central county or counties containing the core, plus adjacent outlying counties having a high degree of social and economic integration with the central county as measured through commuting.
MSA name/number (Metropolitan Statistical Area) The name represents the name of the largest central city and the number is the 4-digit FIPS code.
match candidate resolution The process of resolving an address match when more than one street segment has been identified as corresponding to the input address.
Table 12. N
Term Definition
NAD The North American Datum (NAD) is the official reference ellipsoid used for the primary geodetic network in North America.
NAD27 NAD27 has its origin at Meades Ranch, Kansas. NAD27 does not include the Alaskan islands and Hawaii. Latitudes and longitudes that are surveyed in the NAD27 system are valid only in reference to NAD27 and do not tie to any maps outside the U.S.
NAD83 NAD83 is earth-centered and defined with satellite and terrestrial data. NAD83 is compatible with the World Geodetic System 1984 (WGS84), the terrestrial reference frame associated with the NAVSTAR Global Positioning System (GPS) now used extensively for navigation and surveying. Note that TomTom uses WGS84 instead of NAD83. These two coordinate systems are compatible.
NCSC National Customer Support Center. The U.S.P.S. CASS support center can be reached at www.usps.gov/ncsc.
Table 13. O
Term Definition
object A basic functional unit of a library. A library contains functions that allow the user to create, manipulate, and destroy objects. C programmers access objects through handles that are provided through object creation functions.
Table 14. P
Term Definition
postdirectional (postdir) See directionals.
predirectional (predir) See directionals.
Table 15. R
Term Definition
record matching algorithm Programmed logic that allows evaluation of the results of all field matching algorithms to determine whether two records match (i.e., are duplicates).
road class code A key in the street segment file that identifies a road as major or minor according to the Census Feature Classification Code.
(RR Rural Route) A delivery route served by a rural carrier.
Table 16. S
Term Definition
soundex algorithm A type of field matching algorithm that compares two fields based on their pronunciation.
soundex key Generated by the GsSoundex function. Used to search the database by employing a soundex algorithm.
spatial query functions Used to extract data from the GSD files. These functions specify the area to be searched through a minimum bounding rectangle rather than through city/state/ZIP or finance area.
stage 1 file A sample address file provided by the U.S.P.S to determine if software/hardware meets postal requirements for CASS.
stage 2 file An address file provided by the U.S.P.S. that is used to grade software/hardware to determine if it meets postal requirements for CASS.
street network files Files provided by vendors (other than U.S.P.S.) the contain address and geocode information.
Table 17. T
Term Definition
TomTom A premium data vendor of street segment files (previously known as TeleAtlas).
TIGER files (Topographically Integrated Geographic Encoding and Referencing) A digital database of geographic features created by the US Geological Survey (USGS), covering the entire United States.
TLID (TIGER/Line® Identification Number)

The TIGER/Line® files use a permanent 10-digit TLID to uniquely identify a complete chain for the Nation. The 10-digit TLID will not exceed the value 231-1 (2,147,483,647) and represents the same complete chain in all versions of this file, beginning with the TIGER/Line® Precensus Files, 1990. The minimum value is 100,001. Topological changes to the complete chain causes the TLIDs to change. For instance, when updates split an existing complete chain, each of the new parts receives a new TLID; the old TLID is not reused.

As distributed, TIGER/Line® files are grouped by county (or statistically equivalent entity). A complete chain representing a segment of the boundary between two neighboring counties may have the same TLID code in both counties or it may have different TLID codes even though the complete chain represents the exact same feature on the ground.
Table 18. U
Term Definition
unit designator Indicates the type of unit (e.g., apartment, unit).
USPS data files Files provided by the post office containing address and ZIP Code information.
Table 19. Z
Term Definition
ZIP + 4 directory file Address records that contain the ZIP + 4 codes for all delivery points, in an electronic form.
ZIP + 4 centroid geocoding See geocoding.
ZIP Code (Zone Improvement Plan Code)

Established in 1963 the five-digit numeric code of which the first three digits identify the delivery area of a sectional center facility or a major-city post office serving the delivery address area. The next two (the fourth and fifth) digits identify the delivery area of an associate post office, post office branch, or post office station. All post offices are assigned at least one unique 5-digit code. ZIP Code is a USPS trademark.

ZIP + 4 is an enhanced code consisting of the 5-digit ZIP Code and four additional digits that identify a specific range of delivery addresses. The nine-digit numeric code, established in 1981, composed of two parts: (a) The initial code: the first five digits that identify the sectional center facility and delivery area associated with the address, followed by a hyphen; and (b) the four-digit expanded code: the first two additional digits designate the sector and the last two digits designate the segment. ZIP + 4 is also a USPS trademark.

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