748 Index Term - Chronological (R) (Variable Data Field)
Field definition and scope:
Field 748 contains a chronological term used as an index term that supplements terms derived from data in the MARC classification record. The term may be referred to in the classification number and caption in field 153 (Classification Number).
The field may be used to link a classification number with a related chronological heading. The 748 field provides access to classification numbers 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)). The values in the second indicator position or the data in subfield $2 (Source of heading or term) identify the subject heading system or thesaurus used by an institution to formulate the chronological index term. Index terms not controlled by a thesaurus are contained in field 753 (Index Term - Uncontrolled).
Field 748 is repeatable.
Guidelines for applying content designators:
Field 748 parallels the 648 Subject Added Entry field in the bibliographic format. The indicators and subfield codes below were created from the information in field 648. Examples of field 748 are provided in this section. Guidelines for the input conventions and the source for the content designators are in MARC 21 Format for Bibliographic Data: 648 (Subject Added Entry - Chronological Term).
For indicator and subfield code definitions and examples, and designator repeatability, see table below:
Position |
Description |
Repeatability |
Field 748 |
Index Term - Chronological |
R |
Indicator: |
|
|
First |
Undefined; contains a blank |
|
|
|
|
Second |
|
|
0 |
|
|
1 |
|
|
2 |
|
|
3 |
|
|
4 |
|
|
5 |
|
|
6 |
|
|
7 |
|
|
|
|
|
Subfield code: |
|
|
$a |
NR |
|
$v |
R |
|
$x |
R |
|
$y |
R |
|
$z |
R |
|
$0 |
R |
|
$1 |
R |
|
$2 |
NR |
|
$3 |
NR |
|
$6 |
NR |
|
$8 |
R |
See: Examples for this field.
Subfield $0 - Record control number [redefined, 2010]
Subfield $1 - Real World Object URI [new, 2017]
Related MARC fields or documents:
648 Subject Added Entry - Chronological Term
MARC Code List for Organizations
Source Codes for Vocabularies, Rules, and Schemes:
Subject Heading and Term Source Codes
See also: