Field definition and scope:

Field 650 contains a subject added entry in which the entry element is a topical term.

Topical subject added entries may consist of general subject terms including names of events or objects.  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)].  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).

A title (e.g., Bible and atheism), a geographic name (e.g., Iran in the Koran), or the name of a corporate body (e.g., Catholic Church and humanism) used in a phrase subject heading are also recorded in field 650.

The National level record requirement for this field is Mandatory if applicable.

Field 650 is repeatable.

Guidelines for applying content designators:

The content designators identify the subelements occurring in topical subject and subdivisions and node labels.

For indicator and subfield code definitions and examples, National-level (NLR) and Minimal-level (MLR) record requirements, and designator repeatability, see table below:

Position

Description

NLR

MLR

Repeatability

Field 650

Subject Added Entry - Topical Term

A

O

R

Indicator:

 

 

 

 

First

Level of subject

M

 

 

#

No information provided

A

 

 

0

No level specified

A

 

 

1

Primary

A

 

 

2

Secondary

A

 

 

 

 

 

 

 

Second

Thesaurus

M

 

 

0

Library of Congress Subject Headings

A

 

 

1

LC subject headings for children's literature

A

 

 

2

Medical Subject Headings

A

 

 

3

National Agricultural Library subject authority file

A

 

 

4

Source not specified

A

 

 

5

Canadian Subject Headings

A

 

 

6

Répertoire de vedettes-matière

A

 

 

7

Source specified in subfield $2

A

 

 

 

 

 

 

 

Subfield code:

 

 

 

 

 

Main term portion

 

 

 

$a

Topical term or geographic name entry element

M

O

NR

$b

Topical term following geographic name entry element

A

O

NR

$c

Location of event

A

O

NR

$d

Active dates

A

O

NR

$e

Relator term

A

O

R

$g

Miscellaneous information

A

O

R

$4

Relationship

O

O

R

 

 

 

 

 

 

Subject subdivision portion

 

 

 

$v

Form subdivision

A

O

R

$x

General subdivision

A

O

R

$y

Chronological subdivision

A

O

R

$z

Geographic subdivision

A

O

R

 

 

 

 

 

 

Control subfields

 

 

 

$0

Authority record control number or standard number

O

O

R

$2

Source of heading or term

A

O

NR

$3

Materials specified

O

O

NR

$6

Linkage

A

O

NR

$8

Field link and sequence number

O

O

R

Input conventions:

Ambiguous headings  (what is considered a "topical term")

Punctuation

Spacing

Display constant

Initial article

Content designator history:

Subfield $b - Topical term following geographic name as entry element  [restored]:  Subfield $b was made obsolete in 1981.  The subfield was restored for use in retrospective record conversion in 1987.

Subfield $g - Miscellaneous information  [new, 2014]

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

Subfield $0 - Authority record control number  [redefined, 2010]

Subfield $4 - Relator code  [new, 2005]

Subfield $4 - Relator code  [renamed, 2017] [redescribed, 2017]:  Subfield $4 was renamed to Relationship and redescribed to allow for the recording of relationship URIs in addition to MARC and non-MARC codes.

Related MARC fields or documents:

880  Alternate Graphic Representation

MARC Code List for Relators

Source Codes for Vocabularies, Rules, and Schemes:

Subject Heading and Term Source Codes

See also:

6XX  Subject Access Fields

Variable Data Fields