Library of Congress >> MARC >> Community Information >> 6XX  >> 648

648 - Subject Added Entry-Chronological Term (R)


MARC 21 Community Information - full
December 2017

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

  • $a - Chronological term (NR)

Subject subdivision portion

  • $v - Form subdivision (R)
  • $x - General subdivision (R)
  • $y - Chronological subdivision (R)
  • $z - Geographic subdivision (R)

Control subfields

  • $0 - Authority record control number or standard number (R)
  • $1 - Real World Object URI (R)
  • $2 - Source of heading or term (NR)
  • $3 - Materials specified (NR)
  • $6 - Linkage (NR)
  • $8 - Field link and sequence number (R)


FIELD DEFINITION AND SCOPE

Subject entry in which the first element is a chronological term.

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), 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).


GUIDELINES FOR APPLYING CONTENT DESIGNATORS

Subelements occurring in chronological terms and subdivisions.

INDICATORS

First Indicator - Undefined

Undefined and contains a blank (#).

Second Indicator - Thesaurus

Thesaurus or authority file from which the heading came.

0 - Library of Congress Subject Headings

Added entry conforms to the Library of Congress Subject Headings (LCSH) and the Name authority files. LCSH is maintained by the Library of Congress. Use of Value 0 requires that the heading is appropriate for use in LCSH. Conforms to LCSH is defined as:

  • headings (or headings and subdivisions) found in the LC subject authority file or in the latest edition of LCSH, including the latest microfiche, printed version, CD-ROM, and supplements;
  • headings found in the LC subject authority file or in the latest edition of LCSH to which is added a free-floating or regular subdivision according to the rules stated in the Subject Cataloging Manual: Subject Headings, particularly subdivisions listed in the pattern lists, and geographic subdivisions formulated and applied according to the rules in the manual;
  • headings not printed in LCSH in the past but which have been used by LC and which are not likely to have changed (e.g., names of chemical compounds).
1 - LC subject headings for children's literature

Subject added entry conforms to the "AC Subject Headings" section of Library of Congress Subject Headings (LCSH). LCSH is maintained by the Library of Congress. Use of Value 1 requires that the field is appropriate for the LC Annotated Card Program.

2 - Medical Subject Headings

Subject added entry conforms to the NLM authority files, Medical Subject Headings (MeSH). MeSH is maintained by the National Library of Medicine. Use of value 2 requires that the field is appropriate for use in MeSH.

3 - National Agricultural Library subject authority file

Subject added entry conforms to the National Agricultural Library subject authority file. Use of value 3 requires that the field is appropriate for National Agricultural Library subject heading purposes.

4 - Source not specified

Subject added entry conforms to a controlled list that cannot be identified by 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.

5 - Canadian Subject Headings

Subject added entry conforms to Canadian Subject Headings.Canadian Subject Headings is maintained by Library and Archives Canada.

6 - Répertoire de vedettes-matière

Subject added entry conforms to the Répertoire de vedettes-matière that is maintained by the Bibliothèque de l'Université Laval.

7 - Source specified in subfield $2

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.

SUBFIELD CODES

$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 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.


INPUT CONVENTIONS

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 subfield $v, $x, $y, and $z.


CONTENT DESIGNATOR HISTORY

$0 - Authority record control number [NEW, 2007]
$0 - Authority record control number [REDEFINED, 2010]
$1 - Real World Object URI [NEW, 2017]

Library of Congress >> MARC >> Community Information >> 6XX  >> 648
(12/18/2017)
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