|First Indicator||Second Indicator|
# - Undefined
0 - Library of Congress Subject Headings
1 - LC subject headings for children's literature
2 - Medical Subject Headings
3 - National Agricultural Library subject authority file
4 - Source not specified
5 - Canadian Subject Headings
6 - Répertoire de vedettes-matière
7 - Source specified in subfield $2
Subject subdivision portion
Subject added entry in which the entry element is a geographic name.
Subject added entries are assigned to a bibliographic record to provide access according to generally accepted cataloging and thesaurus-building rules (e.g., Library of Congress Subject Headings (LCSH), Medical Subject Headings (MeSH)). Field 651 may be used by any institution assigning subject headings based on the lists and authority files identified in the second indicator position or in subfield $2 (Source of heading or term).
Jurisdiction names used alone or followed by subject subdivisions are contained in 651 fields. A name of a jurisdiction that represents an ecclesiastical entity is contained in a 610 field. A corporate name, a form subheading, a title of a work, and/or a city section name entered under the name of a jurisdiction are contained in 610 fields. Geographic names used in phrase subject headings (e.g., Iran in the Koran) are contained in 650 fields.
First Indicator - Undefined
Undefined and contains a blank (#).
Second Indicator - Thesaurus
Subject heading system or thesaurus used in constructing the subject heading.
Subject added entry conforms to and is appropriate for use in the Library of Congress Subject Headings (LCSH) and the Name authority files that are maintained by the Library of Congress.
Subject added entry conforms to the "AC Subject Headings" section of the Library of Congress Subject Headings and is appropriate for use in the LC Annotated Card Program.
Subject added entry conforms to and is appropriate for use in the National Library of Medicine authority files.
Subject added entry conforms to and is appropriate for use in the National Agricultural Library subject authority file.
Subject added entry conforms to a controlled list that cannot be identified by second indicator values 0-3, 5-6 or by a code in subfield $2. Field 653 (Index Term-Uncontrolled) is used to record terms that are not derived from controlled subject heading lists.
Subject added entry conforms to and is appropriate for use in the Canadian Subject Headings that is maintained by the Library and Archives Canada.
Subject added entry conforms to the Répertoire de vedettes-matière that is maintained by the Bibliothèque de l'Université Laval.
Subject added entry conforms to a set of subject heading system/thesaurus building rules. The identifying code is given in subfield $2.
$a - Geographic name
Parenthetical qualifying information is not separately subfield coded.
|651||#0$aAltamira Cave (Spain)|
|651||#0$aPompeii (Extinct city)|
|651||#0$aAntietam National Battlefield (Md.)|
|651||#0$aKing Ranch (Tex.)|
|651||#0$aMing Tombs (China)|
|651||#0$aKenwood (Chicago, Ill.)|
|651||#0$aChelsea (London, England)|
|651||#0$aClear Lake (Iowa : Lake)|
$e - Relator term
Designation of the relationship between a geographic name and the described materials, e.g., depicted.
|651||#0$aNiagara Falls (N.Y. and Ont.),$edepicted.|
|651||#0$aBonneville Salt Flats (Utah),$edepicted.|
$g - Miscellaneous information
Data element that is not more appropriately contained in another defined subfield.
$v - Form subdivision
Form subdivision that designates a specific kind or genre of material as defined by the thesaurus being used. Subfield $v is appropriate only when a form subject subdivision is added to a geographic name.
$x - General subdivision
Subject subdivision that is not more appropriately contained in subfield $v (Form subdivision), subfield $y (Chronological subdivision), or subfield $z (Geographic subdivision). Subfield $x is appropriate only when a general topical subdivision is added to a geographic name.
|651||#0$aTexas$xOfficials and employees$xAccidents.|
|651||#0$aAix-en-Provence (France)$xSocial life and customs$vEarly works to 1800.|
|651||#0$aUnited States$xCensus, 2nd, 1800.|
$y - Chronological subdivision
Subject subdivision that represents a period of time. Subfield $y is appropriate only when a chronological subject subdivision is added to a geographic name.
|651||#0$aUruguay$xHistory$yGreat War, 1843-1852.|
|651||#0$aGreece$xHistory$yGeometric period, ca. 900-700 B.C.|
$z - Geographic subdivision
Geographic subject subdivision. Subfield $z is appropriate only when a geographic subject subdivision is added to a geographic name.
$0 - Authority record control number or standard number
$2 - Source of heading or term
MARC code that identifies the source list from which the subject added entry was assigned. It is used only when the second indicator position contains value 7 (Source specified in subfield $2). Code from: Subject Heading and Term Source Codes.
$3 - Materials specified
Part of the described materials to which the field applies.
|651||#7$3Psychiatric admission records$aPennsylvania$xNuclear reactor safety$y1975-1985$zUnited States.$2[thesaurus code]|
$4 - Relator code
MARC code that specifies the relationship between a geographic name and the described materials. Code from: MARC Code List for Relators.
$6 - Linkage
$8 - Field link and sequence number
Ambiguous Headings - See Appendix E.
Punctuation - Punctuation of the subelements of a heading is generally dictated by descriptive cataloging or subject heading system/thesaurus rules. These input conventions clarify MARC punctuation practices. Field 651 ends with a mark of punctuation or a closing parenthesis. If the final subfield is subfield $2 or $3, the mark of punctuation precedes the subfield.
|651||#7$aNew York (N.Y.)$2ericd|
|651||#0$aUnited States$xEconomic policy$y1993-|
Geographic name followed by a subject subdivision does not end with a mark of punctuation unless the name ends with an abbreviation, initial/letter, or open date.
|651||#0$aLouisiana$xPolitics and government$vAnecdotes.|
Spacing - No spaces are used in initialisms, acronyms, or abbreviations.
One space is used between preceding and succeeding initials if an abbreviation consists of more than a single letter.
|651||#0$aVienna (W. Va.)|
|-||[dash associated with the content of subfield $v, $x, $y, and $z]|
Dash (-) that precedes a subdivision in an extended subject heading is not carried in the MARC record. It may be system generated as a display constant associated with the content of subfields $v, $x, $y, and $z.
Initial Articles - Initial articles (e.g., Le) occurring at the beginning of geographic subject added entry fields are usually omitted in most languages (except when the intent is to file on the article). Any diacritics and/or special characters occurring at the beginning of fields are retained. Note that such characters are usually ignored for purposes of sorting and filing.
Subject headings currently formulated in this pattern are contained in field 610.