Field definition and scope:

Field 650 contains a topical subject used as a subject added entry.

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).  Field 650 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).

Field 650 is repeatable.

Guidelines for applying content designators:

For indicator and subfield code definitions and examples, and designator repeatability, see table below:

Position

Description

Repeatability

Field 650

Subject Added Entry - Topical Term

R

Indicator:

 

 

First

Level of subject

 

#

No information available

 

0

No level specified

 

1

Primary

 

2

Secondary

 

 

 

 

Second

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 code:

 

 

$a

Topical term or geographic name as entry element

NR

$b

Topical term following geographic name as entry element

NR

$v

Form subdivision

R

$x

General subdivision

R

$y

Chronological subdivision

R

$z

Geographic subdivision

R

$0

Authority record control number

R

$2

Source of heading or term

NR

$3

Material specified

NR

$6

Linkage

NR

$8

Field link and sequence number

R

Input conventions:

Ambiguous headings

Punctuation

Spacing

Display constant

Initial articles

Content designator history:

Subfield $0 - Authority record control number  [new, 2007]

Related MARC fields or documents:

880  Alternate Graphic Representation

Source Codes for Vocabularies, Rules, and Schemes:

Subject Heading and Term Source Codes

See also:

6XX  Subject Access Fields

Variable Data Fields