| First Indicator | Second Indicator |
|---|---|
| Undefined # - Undefined |
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
|
Subject added entry in which the entry element is a chronological term.
Subject added entries are assigned to a bibliographic record to provide access according to generally accepted thesaurus-building rules (e.g., Library of Congress Subject Headings (LCSH), Medical Subject Headings (MeSH), Faceted Application of Subject Terminology (FAST)). Field 648 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).
Content designators identify the subelements occurring in chronological terms and subdivisions.
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 and/or name authority files maintained by libraries in Canada using French as the language of description.
Subject added entry conforms to a set of subject heading system/thesaurus building rules. The identifying code is given in subfield $2.
$a - Chronological term
| 648 | #7$a1900-1999$2fast | ||||||||
| 648 | #7$a1862$2fast | ||||||||
| 648 | #7$a1800-1899$2fast | ||||||||
$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 subdivision is added to a main 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.
$z - Geographic subdivision
Geographic subject subdivision. Subfield $z is appropriate in field 648 only when a geographic subject subdivision is added to a main term.
$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 added entry was assigned. It is used only when the second indicator position contains value 7 (Source specified in subfield $2). Code from: Subject Heading and Term Source Codes.
| 648 | #7$a1900-1999$2fast | ||||||||
| 648 | #7$a1862$2fast | ||||||||
| 648 | #7$a1800-1899$2fast | ||||||||
$3 - Materials specified
Part of the described materials to which the field applies.
$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.
Display Constant
| - | [dash associated with the content of subfield $v, $x, $y, or $z] |
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 subfield $v, $x, $y, and $z.
Prior to 2013 Indicator 1 was undefined.
Definition of Indicator 1 repealed in 2014 when new field 388 (Time Period of Creation) was approved.