450  See From Tracing - Topical Term (R)  (Variable Data Field)

Field definition and scope:

Field 450 contains a tracing for a topical term see from reference.  It is used in an established heading record or an established heading and subdivision record to trace a see from reference from a topical term not used to an established heading.

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

Field 450 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:

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).

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 $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:

 450  See From Tracing - Topical Term

Tracings and References - 4XX Fields  [General Information]

Related MARC fields or documents:

X50  Topical Terms - General Information

Tracings and References - General Information

RDA in MARC Authority Data

See also:

4XX  See From Tracings

Variable Data Fields