751 Established Heading Linking Entry

Field definition and scope:

Field 751 contains a geographic name that is equivalent to the 151 geographic name or 181 geographic subdivision field of the same record. It links headings within a system or from different thesauri or authority files.

The National level record requirement for this field is Optional.

Field 751 is repeatable.

Guidelines for applying content designators:

The content designators identify the subelements occurring in geographic name headings constructed according to generally accepted cataloging and thesaurus-building conventions [e.g., Anglo-American Cataloguing Rules (AACR 2), Library of Congress Subject Headings (LCSH)].

Jurisdiction names (including those that are ecclesiastical entities) alone or followed by subject subdivisions are X51 geographic names.

A corporate name, a form subheading, a title of a work, and/or a city section name entered under the name of a jurisdiction are contained in the X10 fields.

Geographic names used in phrase subject headings (e.g., Iran in the Koran) are contained in the X50 fields.

A geographic name that is authorized for use only as a subject subdivision part of an extended subject heading is contained in a 181 (Heading - Geographic Subdivision) field.

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

Position	Description	NLR	Repeatability
Field 751	Established Heading Linking Entry - Geographic Name	O	R
Indicator:
First	Undefined; contains a blank	M

Second	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:
$a	Geographic name	M	NR
$g	Miscellaneous information	A	R
$i	Relationship information	A	R
$v	Form subdivision	A	R
$w	Control subfield	A	NR
	/0 Link display	M
	/1 Replacement complexity	A
$x	General subdivision	A	R
$y	Chronological subdivision	A	R
$z	Geographic subdivision	A	R
$0	Authority record control number or standard number	A	R
$1	Real World Object URI		R
$2	Source of heading or term	A	NR
$4	Relationship	O	R
$5	Institution to which field applies	A	R
$6	Linkage	A	NR
$8	Field link and sequence number	O	R

See: Example for this field.

Input conventions:

Ambiguous headings (what is considered a "geographic" name)

Display constant for X51 fields

Display constants for 7XX Linking Entries

Content designator history:

Subfield $g - Miscellaneous information [new, 2014]

Subfield $i - Relationship information [new, 2014]

Subfields $u - Record control number [obsolete, 1997] [USMARC only]

$v - Record control number [redefined, 1995] [USMARC only]

$0 - Record control number [new, 1997]

$0 - Record control number [redefined, 2010]

$v - Form subdivision [redefined, 1995] [USMARC only]

$3 - Authority record control number [obsolete, 1997] [CAN/MARC only]

In USMARC, from 1993 to 1995, subfield $v was defined as Record control number in the 7XX Heading Linking Entry fields. When subfield $v was adapted for form subdivisions in MARC bibliographic and authority heading fields in 1995, subfield $v was redefined as Form subdivision and subfield $u was defined as Record control number. In 1997, subfield $0 was added as Record control number in 5XX and 7XX fields and $u was made obsolete.

Subfield $w/1 - Replacement complexity [new, 2002]: In 2002, subfield $w/1 was defined with the following codes: a (Heading replacement does not require review); b (Heading replacement requires review); and n (Not applicable).

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

Subfield $4 - Relationship code [new, 2014]

Subfield $4 - Relationship 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.

LC Guidelines:

751 Established Heading Linking Entry - Geographic Name

DCM Z1 Instructions:

7XX Heading Linking Entries