| First Indicator | Second Indicator |
|---|---|
| Level of subject # - No information provided 0 - No level specified 1 - Primary 2 - Secondary |
Undefined # - Undefined |
| Subfield Codes | |
|---|---|
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Topical subject entry constructed from a faceted vocabulary.
For each term found in the field, an identification is given as to the facet/hierarchy in the thesaurus from which the term came. In addition, identification is given as to which term is the focus term of the expression. A field may contain more than one expression.
First Indicator - Level of subject
Level of the subject expression or string. This indicator is used to distinguish primary and secondary descriptors.
No information as to the level of the subject expression or string is provided.
Level of the subject expression or string could be determined but is not specified.
Heading: landscape gardens-18th century-United States-Virginia-Charlottesville
| 654 | 0#$cob$alandscape gardens$cy$b18th century$cz$bUnited States$cz$bVirginia$cz$bCharlottesville$2aat | ||||||||
Entry is a primary subject. A subject expression or string is considered primary if it covers the main focus or subject content associated with the community information entity.
Heading: meetings
| 654 | 1#$cac$ameetings$2aat | ||||||||
Entry is a secondary subject. A subject expression or string is considered secondary if it represents a less important aspect associated with the community information entity.
Heading: housing-United States-Illinois-McHenry County
| 654 | 2#$cob$ahousing$cz$bUnited States$cz$bIllinois$cz$bMcHenry County$2aat | ||||||||
Second Indicator - Undefined
Undefined and contains a blank (#).
$a - Focus term
Term is considered the focus term. A focus term is the concrete thing, being, idea, or activity forming the basis of the indexing entry. The subfield is repeated when there is more than one expression in the field.
Heading: French Colonial landscapes-United States-New Jersey
| 654 | ##$csp$bFrench Colonial$cob$alandscapes$cz$bUnited States$cz$bNew Jersey$2aat [The focus term in the AAT expression is "landscapes."] |
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$b - Non-focus term
Term other than that considered the focus.
Heading: garden club-meetings
| 654 | ##$cpo$bgarden club$ameetings$2aat [The focus term in the AAT expression is "meetings."] |
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$c - Facet/hierarchy designation
Designation used by the thesaurus specified by the MARC code contained in subfield $2 to identify the facet/hierarchy for each term contained in subfields $a and $b. Subfield $c always precedes the data to which it is associated.
The designations differ, depending on the subject heading thesaurus used (as specified by the code found in subfield $2). The designations and their associated facets/hierarchies can be found in the thesaurus identified by subfield $2.
Heading: housing-United States-Florida-Miami
| 654 | ##$cob$ahousing$cz$bUnited States$cz$bFlorida$cz$bMiami$2aat | ||||||||
$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 faceted topical term.
$y - Chronological subdivision
Subject subdivision that represents a period of time. Subfield $y is appropriate only when a chronological subject subdivision is added to a main term.
| 654 | 0#$cr$alandscape$y18th century$zEngland.$2aat | ||||||||
$z - Geographic subdivision
Geographic subject subdivision. Subfield $z is appropriate in field 650 only when a geographic subject subdivision is added to a main term.
| 654 | 0#$cr$alandscape$y18th century$zEngland.$2aat | ||||||||
$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.
$2 - Source of heading or term
MARC code that identifies the source list from which the subject expression was assigned. Code from: Subject Heading and Term Source Codes.
Heading: country houses-United States-Kentucky
| 654 | ##$cob$acountry houses$cz$bUnited States$cz$bKentucky$2aat | ||||||||
$3 - Materials specified
Part of the collection, etc. to which the field applies.
Heading: business letters: housing-United States
| 654 | ##$3business letters$cr$ahousing$cz$bUnited States.$2aat | ||||||||
$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.
Punctuation - The subfield preceding subfield $2 in field 654 ends with a mark of punctuation or a closing parenthesis.
Display Constant - The dash (-) that precedes any non-focus term that follows a focus term, that precedes a second, etc. focus term, or that precedes a subdivision is not carried in the machine-readable record. It may be system generated as a display constant associated with the content of subfields $a, $b, $v, $y, and $z.