| First Indicator | Second Indicator |
|---|---|
| Level of subject # - No information available 0 - No level specified 1 - Primary 2 - Secondary |
Thesaurus 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 |
| Subfield Codes | |
|---|---|
|
Main term portion
Subject subdivision portion
|
Control subfields
|
Topical subject used as a subject added entry.
Subject added entries are assigned to a community information record to provide access according to generally accepted thesaurus-building rules (e.g., Library of Congress Subject Headings (LCSH), Medical Subject Headings (MeSH)). Field 650 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 $2 (Source of heading or term).
First Indicator - Level of subject
Level of the subject entry. This indicator is used to distinguish primary and secondary descriptors.
Level of the subject term could be determined but is not specified.
| 650 | 00$aImmunization. | ||||||||
Entry is a primary subject. A subject is considered primary if it covers the main focus or subject content associated with the community information entity.
| 650 | 17$aCareer Exploration.$2ericd | ||||||||
| 650 | 17$aCooks.$2ericd | ||||||||
Entry is a secondary subject. A subject is considered secondary if it represents a less important aspect associated with the community information entity.
| 650 | 17$aFood Service.$2ericd | ||||||||
| 650 | 27$aJunior High Schools.$2ericd [Primary and secondary subject content identified.] |
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Second Indicator - Thesaurus
Name and/or 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) that is maintained by the Library of Congress. Conforms to LCSH is defined as:
Subject added entry conforms to the "AC Subject Headings" section of Library of Congress Subject Headings and is appropriate for use in the LC Annotated Card Program. LCSH is maintained by the Library of Congress.
Subject added entry conforms to and is appropriate for use in Medical Subject Headings (MeSH) and/or the NLM name authority files. MeSH is maintained by the National Library of Medicine.
Subject added entry conforms to the U.S. National Agricultural Library subject authority file. Requires that the field is appropriate for NAL subject heading purposes.
Subject added entry conforms to a controlled list but the source cannot be specified by one of the subject heading system/thesauri covered by second indicator values 0-3, 5-6 or by a code for a specific subject heading list 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 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 other than that specified by one of the other defined values and for which identifying codes are given in subfield $2. Codes from: Subject Heading and Term Source Codes.
$a - Topical term or geographic name as entry element
Topical subject or a geographic name used as an entry element for a topical term. Parenthetical qualifying information associated with the term is not separately subfield coded.
| 650 | #0$aMeals on wheels programs. | ||||||||
| 650 | #0$aNursing home care. | ||||||||
| 650 | #0$aNutrition disorders. | ||||||||
| 650 | #0$aConcertos (String orchestra) | ||||||||
| 650 | #0$aVocal music$zFrance$y18th century. | ||||||||
| 650 | #0$aDentistry$xResearch. | ||||||||
$b - Topical term following geographic name as entry element
Topical term that is entered under a geographic name contained in subfield $a.
| 650 | #0$aCaracas.$bBolivar Statue. | ||||||||
$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 main term.
$x - General subdivision
Subject subdivision that is not more appropriately contained in subfields $v (Form subdivision, $y (Chronological subdivision) or $z (Geographic subdivision). Subfield $x is appropriate only when a general topical or form subject subdivision is added to a main term.
| 650 | #0$anumismatics$xCollectors and collecting. | ||||||||
$y - Chronological subdivision
Subject subdivision that represents a period of time. Subfield $y is appropriate only when a chronological subject subdivision is added to a main term.
| 650 | #0$aMusic$y500-1400. | ||||||||
$z - Geographic subdivision
Geographic subject subdivision. Subfield $z is appropriate only when a geographic subject subdivision is added to a main term.
| 650 | #0$aHousing rehabilitation$zGeorgia. | ||||||||
| 650 | #0$aReal property$zMississippi$zTippah County. | ||||||||
$0 - Authority record control number or standard number
See description of this subfield in Appendix A: Control Subfields.
$1 - Real World Object URI
See description of this subfield in Appendix A: Control Subfields.
$2 - Source of heading or term
MARC code that identifies the source list from which the heading or term in a Subject Added Entry field was assigned. Code from: Subject Heading and Term Source Codes.
Used only when the second indicator position contains value 7 (Source specified in subfield $2).
| 650 | #7$aFood Service.$2ericd | ||||||||
$3 - Materials specified
Part of the described materials to which the field applies.
$6 - Linkage
See the description of this subfield in Appendix A: Control Subfields.
$8 - Field link and sequence number
See the description of this subfield in Appendix A: Control Subfields.
Ambiguous Headings - See Appendix D.
Punctuation - Field 650 ends with a mark of punctuation or a closing parenthesis. If the final subfield is subfield $2, the mark of punctuation or closing parenthesis precedes the subfield.
| 650 | #0$aBallads, American$zHudson River Valley (N.Y. and N.J.) | ||||||||
| 650 | 17$aCareer Exploration.$2ericd | ||||||||
A topical term followed by a subject subdivision does not end with a mark of punctuation unless the topical term ends with an abbreviation, initial/letter, or open date.
| 650 | #0$aMental health counseling$zWashington (State)$zSeattle. | ||||||||
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 phrase.
Display Constant - The dash ( - ) that precedes a subject subdivision in an extended subject heading is not carried in the machine-readable record. It may be system generated as a display constant associated with the content of subfields $x, $y, and $z.
Initial Articles - Initial articles (e.g., The) occurring at the beginning of topical 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.