| First Indicator | Second Indicator |
|---|---|
| Undefined # - Undefined |
180/480/580 - Undefined # - Undefined 780 - 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 | |
|---|---|
|
Subject subdivision portion
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Tracing and linking subfields
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Content designators identify the subelements occurring in general subdivision headings constructed according to generally accepted thesaurus-building conventions (e.g., Library of Congress Subject Headings, Medical Subject Headings). A general subdivision may be a topical or language term that is used as a subdivision portion of an extended subject or index term access field in bibliographic records. A topical or language term that is used as the lead element of an established heading record is contained in a 150 (Heading-Topical Term) field.
Only generally-applicable content designators are described in full in this section. A small number of content designators with field-specific instructions are described in the Tracings and References-General Information section (for field 480 and 580) and the 7XX Heading Linking Entries-General Information section (for field 780).
First Indicator - Undefined
Undefined and contains a blank (#).
Second Indicator
In fields 180, 480, and 580, the second indicator position is undefined and contains a blank (#). For field 780, the second indicator position contains one of the values described in the 7XX Heading Linking Entries-General Information section.
$i - Relationship information [480/580/780]
Designation of a relationship of the entity in a 480, 580, or 780 field to the 1XX entity in the record or a textual reference instruction phrase. For fields 480 and 580 the phrase may be system-generated from the field tag or from the codes defined for subfield $w (Control subfield). Subfield $i is appropriate only in fields 480, 580, and 780. Guidelines for using subfield $i in fields 480 and 580 are provided in the Tracings and References-General Information section. Guidelines for using subfield $i in field 780 are provided in the 7XX Heading Linking Entries-General Information section.
$v - Form subdivision
Designates a specific kind or genre of material as defined by the thesaurus being used. Subfield $v is appropriate in an X80 field only when a form subject subdivision is added to a general subdivision to form an extended heading.
| 180 | ##$xRussian$vDictionaries | ||||||||
$w - Control subfield [480/580/780]
Codes in one or more character positions defined to control the display of information and specify relationships, restrictions, and status. Subfield $w is appropriate only in field 480, 580, and 780. Character position definitions and guidelines for applying the codes defined for subfield $w in field 480 and 580 are provided in the Tracings and References-General Information section. Character position definitions and guidelines for field 780 are in the 7XX Heading Linking Entries-General Information section.
$x - General subdivision
Topical or language subdivision term.
| 180 | ##$xPolitical aspects | ||||||||
| 180 | ##$xRhetoric$xAbility testing | ||||||||
| 180 | ##$xArabic | ||||||||
$y - Chronological subdivision
Subdivision term that represents a period of time. Subfield $y is appropriate in an X80 field only when a chronological subdivision is added to a general subdivision to form an extended subdivision heading.
| 180 | ##$xCivilization$y16th century | ||||||||
| 180 | ##$xHistory$y18th century$xExhibitions | ||||||||
| 180 | ##$xHistory of doctrines$yEarly Church, ca. 30-600 | ||||||||
$z - Geographic subdivision
Appropriate in an X80 field only when a geographic subdivision is added to a general subdivision to form an extended subdivision heading.
| 180 | ##$xBoundaries$zCanada | ||||||||
| 180 | ##$xNuclear reactor safety$y1975-1985$zUnited States | ||||||||
| 180 | ##$xCampaigns$zTunisia | ||||||||
$0 - Authority record control number or standard number [580/780]
See description of this subfield in Appendix A: Control Subfields.
$1 - Real World Object URI [580/780]
See description of this subfield in Appendix A: Control Subfields.
$2 - Source of heading or term [780]
Code that identifies the source of a heading or term when the second indicator position contains value 7. Subfield $2 is appropriate only in field 780. Guidelines for applying subfield $2 are provided in the 7XX Heading Linking Entries-General Information section.
$4 - Relationship [480/580/780]
Code or URI that specifies the relationship from the entity described in the record to the entity referenced in the field. Guidelines for using subfield $4 in fields 480 and 580 are provided in the Tracings and References-General Information section. Guidelines for using subfield $4 in field 780 are provided in the 7XX Heading Linking Entries-General Information section.
$5 - Institution to which field applies [480/580/780]
See description of this subfield in Appendix A: Control Subfields.
$6 - Linkage
See description of this subfield in Appendix A: Control Subfields.
$8 - Field link and sequence number
See description of this subfield in Appendix A: Control Subfields.
Punctuation - Punctuation of the subelements of a heading is generally dictated by subject heading system/thesaurus rules. These input conventions clarify MARC punctuation practices. An X80 field does not end with a mark of punctuation unless the field ends with an abbreviation or data that ends with a mark of punctuation.
| 180 | ##$xSalaries, etc. | ||||||||
| 180 | ##$xEconomic conditions$y1960- | ||||||||
Spacing - No spaces are used in initialisms.
| 180 | ##$xHistory$y332-30 B.C. | ||||||||
One space is used between the final period of an abbreviated term and a word or numeral that follows.
| 180 | ##$xHistory$yEarly church, ca. 30-600 | ||||||||
Display Constant
| - | [dash associated with the content of subfield $v, $x, $y, and $z] |
Dash (-) that precedes a subdivision in an extended heading is not carried in the MARC record. It may be system generated as a display constant associated with the content of subfield $v, $x, $y, and $z.
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Content designated field :
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| 180 | ##$xEconomic conditions$y1960- | ||||||||
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Display example: Economic conditions-1960-
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Subfield $4 was renamed and redescribed to allow for the recording of relationship URIs in addition to MARC and non-MARC codes.