|First Indicator||Second Indicator|
# - Undefined
# - Undefined
Geographic area codes (GAC) associated with the geographic aspect of the classification number and caption in field 153 (Classification Number). Source of the code in subfield $a is 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.
$a - Geographic area code
Seven-character MARC code for a geographic area. Each geographic area code associated with a heading is contained in a separate subfield $a.
|153||##$z2$a663$z2$e66$hGeographic Areas, Historical Periods, Biography$kSpecific continents, countries, localities; extraterrestrial worlds$kModern world; extraterrestrial worlds$kAfrica$kWest Africa and offshore islands$jSenegal|
$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 $a for international exchange and understanding.
|043||##$as-bl---$bs-bl-ba$2 [source of local code]
[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
Code that identifies the 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 alphabetical 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.