|First Indicator||Second Indicator|
# - Undefined
# - Undefined
Geographic area codes associated with an item. Code from: MARC Code List for Geographic Areas. The source of a local code in subfield $b is indicated in subfield $2. The source of codes in subfield $c is ISO 3166, Codes for the representation of names of countries and their subdivisions - Part 1 : Country codes or Part 2 : Country subdivision codes.
More precise identification of geographic areas associated with a bibliographic record may be contained in field 052 (Geographic Classification Code). Subfield $b may be used for a local expansion of a GAC code.
Choice of geographic area code is usually based on the geographic names and/or subdivisions in 6XX subject added entry and index term fields. GACs are recorded in field 043 in order of importance, which is generally the same order as the geographic names and/or subdivisions in the 6XX fields.
$a - Geographic area code
Seven-character MARC code for a geographic area. Each geographic area code associated with an item is contained in a separate subfield $a.
[Item represented by record related to the U.S., France, and Japan.]
[Item represented by record related to the Great Lakes region.]
[Item represented by record related to West Africa.]
[Item represented by record related to Nepal.]
[Item represented by record related to Maryland.]
[Collection of steamboat records relating to steamboats operating in the Ohio and Mississippi valleys.]
$b - Local GAC code
Code is formulated by attaching a local subentity code to an already established geographic area code. Each local GAC associated with an item is contained in a separate subfield $b. It is recommended that standard GACs also be included in subfield $a for international exchange and understanding.
[Item represented by record related to the state of Bahia in Brazil.]
$c - ISO code
Code taken from the International Organization for Standardization's Codes for the representation of names of countries and their subdivisions - Part 1: Country codes or Part 2 : Country subdivision codes (ISO 3166).
[Contains an ISO 3166-1 code for the United States with no corresponding MARC GAC code.]
$0 - Authority record control number or standard number
$2 - Source of local code
Source from which the local code was assigned. Used only when subfield $b is used to indicate a local GAC code.
Code from: Geographic Area Code and Term Source Codes.
$6 - Linkage
$8 - Field link and sequence number
Structure - All alphabetic characters are input in lowercase. Embedded and trailing hyphens are carried in the MARC record. A detailed description of the structure and use of GACs is contained in MARC Code List for Geographic Areas.
Subfield $c was defined to accommodate ISO 3166 country codes.