X55 Genre/Form Terms - General Information

Field definition and scope:

Each genre/form term field is unique in its definition and scope. For specific information, select from the list below.

455 See From Tracing - Genre/Form Term (R)

755 Established Heading Linking Entry - Genre/Form Term (R)

Record requirements: The National level record requirement for the genre/form term fields is Mandatory if applicable, except for field 755 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 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.

The indicators, subfield codes, and input conventions for the genre/form term fields 155, 455, 555, and 755 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 X55	Genre/Form Terms	*	*
Indicator:
First	Undefined; contains a blank	M

Second
155, 455, 555	Undefined; contains a blank	M

755	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:
	Main term portion
$a	Genre/form term	M	NR

	Subject subdivision portion
$v	Form subdivision	A	R
$x	General subdivision	A	R
$y	Chronological subdivision	A	R
$z	Geographic subdivision	A	R

	Tracing and linking subfields
$i	Relationship information [455, 555, 755]	current - A earlier - A	R
$w	Control subfield [455, 555, 755]	A	NR
$0	Authority record control number or standard number [555, 755]	A	R
$1	Real World Object URI [555, 755]		R
$2	Source of heading or term [755]	A	NR
$4	Relationship [455, 555, 755]	O	R
$5	Institution to which field applies [455, 555, 755]	A	R
$6	Linkage	A	NR
$8	Field link and sequence number	O	R

Input conventions:

Punctuation

Spacing

Display constant for X55 fields

Content designator history:

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

Subfield $i - Reference instruction phrase [455, 555] [redefined, 2009]

Subfield $i - Relationship information [755] [new, 2014]

Subfields $u - Record control number [755] [obsolete, 1997] [USMARC only]

$v - Record control number [755] [redefined, 1995] [USMARC only]

$0 - Record control number [555, 755] [new, 1997]

$0 - Record control number [555, 755] [redefined, 2010]

$v - Form subdivision [redefined, 1995]

$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 $1 - Real World Object URI [555, 755] [new, 2017]

Subfield $4 - Relationship code [455, 555] [new, 2009]

Subfield $4 - Relationship code [755] [new, 2014]

Subfield $4 - Relationship code [455, 555, 755] [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.