550 See Also From Tracing

Field definition and scope:

Field 550 contains a tracing for a topical term see also from reference. It is used in an established heading record or an established heading and subdivision record to trace a see also from reference from an established topical term to a related established heading.

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

Field 550 is repeatable.

Guidelines for applying content designators:

The content designators identify the subelements occurring in topical term and node label headings constructed according to generally accepted thesaurus-building conventions (e.g., Library of Congress Subject Headings).

Topical terms include occupation and function terms that are used as the lead element of subject or added entry access fields in bibliographic records.

A topical term that is authorized for use only as a subject subdivision part of an extended subject heading is contained in a 180 (General Subdivision) or 182 (Chronological 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 550	See Also From Tracing - Topical Term	A	R
Indicator:
First	Undefined; contains a blank	M
Second	Undefined; contains a blank	M

Subfield code:
$a	Topical term or geographic name entry element	M	NR
$b	Topical term following geographic name entry element	A	NR
$g	Miscellaneous information	A	R
$i	Relationship information	current - A earlier - A	R
$v	Form subdivision	A	R
$w	Control subfield	A	NR
	/0 Special relationship	O
	/1 Tracing use restriction	O
	/2 Earlier form of heading	O
	/3 Reference display	O
$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
$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:

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

Punctuation

Spacing

Display constant for X50 fields

Display constants for cross references

Content designator history:

Second Indicator - Nonfiling characters [obsolete]: The second indicator position was made obsolete in fields 150, 450, and 550 in 1993. The values were: 0-9 (Number of nonfiling characters present).

Subfield $g - Miscellaneous information [new, 2014]

Subfield $i - Reference instruction phrase [redefined, 2009]: Subfield $i was renamed Relationship information and broadened to include relationship designations in addition to textual reference phrases. The subfield was changed from Not repeatable (NR) to Repeatable (R).

Subfields $v - Form subdivision [redefined]

$0 - Record control number [new, 1997]

$0 - Record control number [redefined, 2010]

$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. In 1997, subfield $0 was added as Record control number in 5XX and 7XX fields.

Subfield $w/0 - Print constant code [redefined, 1997] [CAN/MARC only]: The following values were redefined: g (Full name), h (Real name), and i (Real name (reputedly)). The following values were made obsolete: j (Name originally), k (Name in religion), l (Secular name), m (Stage name of), o (Variant name), p (Abbreviated name), q (Official name), r (Broader term), s (Narrower term), x (Print constant generated from tag value), and z (Text carried in subfield $i).

Subfield $w/0 - Special relationship

Code r - Relationship information in subfield $i or $4 [new, 2009]

Subfield $w/1 - Tracing use restriction

Code h - No reference structures [new, 2007]

Subfield $w/2 - Earlier form of heading

Code x - Tracing is not the form of heading established under earlier cataloguing rules [obsolete, 1997] [CAN/MARC only]

Subfield $w/3 - Reference display

Code e - Note only generated from the tracing [obsolete, 1997] [CAN/MARC only]

Code i - Invisible see from reference [obsolete, 1997] [CAN/MARC only]

Code x - Reference is generated from the tracing [obsolete, 1997] [CAN/MARC only]

Subfield $w/4 - Formerly established heading code [obsolete, 1997] [CAN/MARC only]: The following values were defined: d (Formerly accepted heading replaced by the heading in the 1XX field), s (Formerly accepted heading replaced by other headings, one of which is in the 1XX field), and x (Not a formerly accepted heading).

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

Subfield $4 - Relationship code [new, 2009]

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:

Tracings and References - 5XX Fields [General Information]