755 Established Heading Linking Entry

Field definition and scope:

Field 755 contains a genre/form term that is equivalent to the 155 genre/form term or 185 form subdivision heading 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 755 is repeatable.

Guidelines for applying content designators:

The content designators identify the subelements occurring in genre/form term headings constructed according to generally accepted thesaurus-building conventions (e.g., Art & Architecture Thesaurus).

Genre terms for textual materials designate specific kinds of materials distinguished by the style or technique of their intellectual contents; for example, biographies, catechisms, essays, hymns, or reviews.

Form terms designate historically and functionally specific kinds of materials as distinguished by an examination of their physical character, characteristics of their intellectual content, or the order of information within them; for example, daybooks, diaries, directories, journals, memoranda, questionnaires, syllabi, or time sheets.

In the context of graphic materials, genre headings denote categories of material distinguished by vantage point, intended purpose, characteristics of the creator, publication status, or method of representation.

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

Position	Description	NLR	Repeatability
Field 755	Established Heading Linking Entry - Genre/Form Term	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	Genre/form term as entry element	M	NR
$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: Examples for this field.

Input conventions:

Display constant for X55 fields

Display constants for 7XX Linking Entries

Content designator history:

Prior to the definition of the X55 fields, X50 (Topical Terms) fields were used for genre/form term headings.

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:

755 Established Heading Linking Entry - Genre/Form Term

DCM Z1 Instructions:

7XX Heading Linking Entries