ACG See Address Coding Guide.
Active governmental unit A governmental unit that has elected or appointed
officials, raises revenues, and performs governmental activities (such as enact-
ment of laws, provision of services, and entering into contracts). See also func-
tional status (governmental), functioning governmental unit, inactive governmental
unit, nonfunctioning governmental unit.
Address The number or other designation assigned to a housing unit, busi-
ness establishment, or other structure for purposes of mail delivery, emer-
gency services, and so forth. See also city-style address, general delivery address,
post office box address, rural address.
Address coding guide (ACG) A computerized inventory of street names,
address ranges, and census block numbers, created by the Census Bureau
in cooperation with local agencies, to permit the automated assignment of
addresses on a mailing list to the geographic entity codes for the 145 larg-
est urban cores of metropolitan areas (MAs) at the time of the 1970 census.
Each file contained the name of each block side that was a street or road,
its associated address range and ZIP Code, and 1970 census geographic
entity information for that side of the street. It was the forerunner of the
GBF/DIME-Files and the TIGER data base. See also GBF/DIME-File, TIGER
Address Reference File (ARF) A series of computerized files containing street
and building records used to geocode the economic censuses. The files
show, by ZIP Code, the low and high addresses associated with each street
name within incorporated places of 2,500 or more population, special eco-
nomic urban areas (SEUAs) of 10,000 or more population, balances of
counties, and balances of (S)MSAs.
Address register area (ARA) A geographic entity established by the Census
Bureau for 1990 census data collection purposes. It usually consists of a cen-
sus tract or block group. See also enumeration district, tape address register.
Adjacent A term descriptive of geo