X80 General Subdivisions - General Information

Field definition and scope:

Each general subdivision field is unique in its definition and scope. For specific information, select from the list below.

180 Heading - General Subdivision (NR)

480 See From Tracing - General Subdivision (R)

780 Subdivision Linking Entry - General Subdivision (R)

Record requirements: The National level record requirement for the general subdivision fields is Mandatory if applicable, except for field 780 which is Optional. For the national level requirements by subfield, see the specific field.

Field repeatability: See the specific field for its repeatability.

Guidelines for applying content designators:

The content designators identify the subelements occurring in general subdivision headings constructed according to generally accepted thesaurus-building conventions (e.g., Library of Congress Subject Headings, Medical Subject Headings).

A general subdivision may be a topical or language term that is used as a subdivision portion of an extended subject or index term access field in bibliographic records.

A topical or language term that is used as the lead element of an established heading record is contained in a 150 (Heading - Topical Term) field.

The indicators, subfield codes, and input conventions for the general subdivision fields 180, 480, 580, and 780 follow similar patterns. Guidelines for applying them are below. Subfields are grouped by type of entry.

For indicator and subfield code definitions and examples, National level (NLR) record requirements, and designator repeatability, see table below. An asterisk ( * ) in the column indicates that the requirement varies. See table in the specific field.:

Position	Description	NLR	Repeatability
Field X80	General Subdivisions	*	*
Indicator:
First	Undefined; contains a blank	M

Second
180, 480, 580	Undefined; contains a blank	M

780	Thesaurus	M
0	Library of Congress Subject Headings/Name authority file	A
1	LC subject headings for children's literature	A
2	Medical Subject Headings/NLM name authority file	A
3	National Agricultural Library subject authority file	A
4	Source not specified	A
5	Canadian Subject Headings/LAC name authority file	A
6	Répertoire de vedettes-matière	A
7	Source specified in subfield $2	A

Subfield code:
	Subject subdivision portion
$v	Form subdivision	A	R
$x	General subdivision	M	R
$y	Chronological subdivision	A	R
$z	Geographic subdivision	A	R

	Tracing and linking subfields
$i	Relationship information [480, 580, 780]	current - A earlier - A	R
$w	Control subfield [480, 580, 780]	A	NR
$0	Authority record control number or standard number [580, 780]	A	R
$1	Real World Object URI [580, 780]		R
$2	Source of heading or term [780]	A	NR
$4	Relationship [480, 580, 780]	O	R
$5	Institution to which field applies [480, 580, 780]	A	R
$6	Linkage	A	NR
$8	Field link and sequence number	O	R

Input conventions:

Punctuation

Spacing

Display constant for X80 fields

Content designator history:

Subfield $i - Reference instruction phrase [480, 580] [redefined, 2009]

Subfield $i - Relationship information [780] [new, 2014]

Subfield $0 - Record control number [580, 780] [redefined, 2010]

Subfield $1 - Real World Object URI [580, 780] [new, 2017]

Subfield $4 - Relationship code [480, 580] [new, 2009]

Subfield $4 - Relationship code [780] [new, 2014]

Subfield $4 - Relationship code [480, 580, 780] [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.