MARC 21 Format for Authority Data: tref: Tracings and References-General Information (Network Development and MARC Standards Office, Library of Congress)

This is an ARCHIVED VERSION of the 2009/2010 electronic edition of the MARC 21 Concise Formats. Please see loc.gov/marc/concise/ for the most up-to-date version of the electronic MARC 21 Concise Formats.

INTRODUCTION

Cross references lead from an unauthorized heading to an authorized heading (see reference) or from one authorized heading to another (see also reference). Actual cross references are generally not carried explicitly in authority records. Instead, variant form and related headings are carried in authority records in either tracing or reference note fields. Cross reference displays may be generated by combining the contents of a tracing or a reference note field and the 1XX heading field of a record.

In the MARC 21 Authority format, a variety of tracing and reference fields are defined to allow the generation of simple and complex references. These data elements are divided into the following groups where descriptions of specific fields can be found:

TRACING FIELDS

Tracing fields lead directly from one heading to a single other heading. A 4XX (See From Tracing) field leads from an unauthorized heading to an authorized heading. A 5XX see also from tracing field leads from one authorized heading to another authorized heading. The 4XX and 5XX fields are used only in established heading records and subdivision records.

Cross reference displays generated from the tracing fields are called simple cross references. In a simple cross reference display, the content of the 4XX or 5XX field is the heading referred from, and, following a reference instruction phrase, the content of the 1XX field is the heading referred to. In the tracing fields, the reference instruction phrase may be implicitly associated with either the field tag or a code in subfield $w/0 (Special relationship). In some cases, the reference instruction phrase may be carried explicitly in subfield $i (Relationship information) or associated with a relationship designation expressed in subfield $i or, in coded form in subfield $4.

REFERENCE NOTE FIELDS

Reference note fields lead from one heading to one or more other headings. A reference note field is used when more complex reference instruction is needed than can be conveyed by one or more simple cross references generated from 4XX and/or 5XX fields. Cross reference displays generated from the reference note fields are complex cross references. In a complex cross reference display, the content of the 1XX field of a record is the heading referred from, and, following a reference instruction phrase, the reference note field contains the heading(s) referred to. In field 260 and 360, the complete reference instruction may be a combination of a phrase implicitly associated with the field tag and explicit text in subfield $i (Explanatory text). In field 663, 664, 665, and 666, the reference instruction text is contained in subfield $a (Explanatory text).

There are two types of reference note fields: 1) those used in records for established headings; and 2) those used in reference records. The fields used for see also reference notes (field 360, 663, and 665) are used to lead from an established heading to other established headings. The fields used for see reference notes (field 260, 664, and 666) are used in reference records to lead from an unestablished heading to established headings.

Current cataloging practice does not encourage the use of a reference note field if cross references generated from tracings in one or more 4XX and/or 5XX fields will provide satisfactory user guidance. For example, instead of carrying a 665 history reference field in each of the established heading records involved in corporate body name changes, each name is traced in a 4XX or 5XX field. The earlier or later name relationship between each 4XX or 5XX field and the 1XX field is indicated by a code in subfield $w/0 (Special relationship).

SIMPLE CROSS REFERENCE FIELDS

Simple cross references are generated for display from tracing fields. The following description related to the tracing fields is arranged by the source of the reference instruction phrase used in the cross reference: tag related, subfield $i, and subfield $w. The character positions defined for subfield $w are also described here.

Tag Related Reference Instruction Phrase

Reference instruction phrase such as see: or search under: may be implicitly associated with a 4XX field tag and may be used to generate a display of a cross reference. Reference instruction phrase such as see also: or search also under: may be implicitly associated with a 5XX field and may be used to generate a display of a cross reference.

$i - Relationship information

Subfield may contain either a designation of a relationship of the entity in a 4XX or 5XX field to the 1XX entity in the record or it may contain a textual reference instruction phrase that is to be used for a user display indicating the relationship of the 1XX entity in the record to the entity in a 4XX or 5XX field. If the subfield contains a Relationship designation, the appropriate reference instruction phrase may be derived from it. The relationship may be name to name (if only names of persons, families, or corporate bodies are involved) or resource to resource (if name/titles or titles are involved).

Relationship designation: When a tracing field contains a relationship designation in subfield $i, control subfield $w/0 contains code r (Relationship designation in subfield $i or $4). Code r indicates that the generation of a tag related reference instruction phrase in a cross reference display should be suppressed. The content of subfield $i or $4 should be used to generate the reference instruction phrase that is used in a cross reference display.

$4 - Relationship code

Contains in coded form the designation of a relationship of the entity in a 4XX or 5XX field to the 1XX entity in the record. See subfield $i for further information on relationship designators.

$w - Control subfield

Up to four character positions (designated as $w/0, etc.) that indicate whether special instructions apply to the display of the heading in the 4XX or 5XX field and whether a tracing is restricted to the reference structure of a particular type of authority. Subfield $w need not be used if none of the characteristics is applicable. Because the definitions of the codes in subfield $w are dependent on the character position in which they occur, the coding of any character position mandates that each preceding character position contains a code or a fill character (|); succeeding character positions need not be used. For example, if $w/0 and $w/1 are not applicable but $w/2 is applicable, then $w/0 and $w/1 each contain code n (Not applicable) or a fill character (|).

/0 - Special relationship

One-character alphabetic code that describes a relationship of an entity in a 4XX or 5XX field to that in the 1XX field that is more specific than the relationship implicit in the tag. The codes may be used to generate a special reference instruction phrase in a cross reference display.

a - Earlier heading

Established heading in the tracing field is an earlier name for the heading in the 1XX field. The code may be used to generate a special reference instruction phrase such as search also under the later heading: in a cross reference display.

b - Later heading

Heading in the tracing field is a later name for the heading in the 1XX field. The code may be used to generate a special reference instruction phrase such as search also under the earlier heading: in a cross reference display.

d - Acronym

Heading in the tracing field is an acronym for the heading in the 1XX field. The code may be used to generate a special reference instruction phrase such as search under the full form of the heading: in a cross reference display.

f - Musical composition

Heading in the 4XX or 5XX field is for a literary work upon which the musical composition in the heading in the 1XX field is based. The code may be used to generate a special reference instruction phrase such as for a musical composition based on this work, search also under: in a cross reference display.

g - Broader term

Heading in the 4XX or 5XX field is a broader term than the heading in the 1XX field. The code may be used to generate a special reference instruction phrase such as search also under the narrower term: in a cross reference display.

h - Narrower term

Heading in the 4XX or 5XX field is a narrower term than the heading in the 1XX field. The code may be used to generate a special reference instruction phrase such as search also under the broader term: in a cross reference display.

i - Reference instruction phrase in subfield $i

Used in conjunction with subfield $i (Relationship information). Guidelines for applying code i are given under the description of subfield $i.

n - Not applicable

Relationship between the heading in the 4XX or 5XX field and the heading in the 1XX field is not one of the special relationships for which other codes are defined in subfield $w/0. A tag related reference instruction phrase such as search under: or search also under: may be used in a cross reference display from the related heading. If code n is applicable, subfield $w/0 need not be coded unless a subsequent character position is required.

r - Relationship designation in subfield $i or $4

Used in conjunction with subfield $i (Relationship information) or subfield $4 (Relationship code). Guidelines for applying code i are given under the description of subfield $i.

t - Immediate parent body

Heading in the 5XX field is the name of a parent body of the entity in the 1XX field. Code t is applicable only to corporate bodies. It may be used for archival material where there is a need to identify fully the hierarchical structure of a corporate entity.

/1 - Tracing use restriction

One-character alphabetic code that specifies the authority reference structure in which the use of a 4XX or 5XX field to generate a cross reference is appropriate. When the tracing reference structure use differs from the use of the heading in the 1XX field, a tracing use restriction code in subfield $w/1 enables suppression or generation of the cross reference as required for the type of reference structure.

a - Name reference structure only

b - Subject reference structure only

c - Series reference structure only

d - Name and subject reference structures

e - Name and series reference structures

f - Subject and series reference structures

g - Name, subject, and series reference structures

h - No reference structures

n - Not applicable

/2 - Earlier form of heading

One-character alphabetic code that indicates whether the heading in the 4XX field is an earlier form in which the name or subject was established either in the relevant national authority file or in an authority file other than the national authority file.

a - Pre-AACR 2 form of heading (national name authority file)

Heading in the 4XX field is a pre-AACR2 form (of the heading in the 1XX field) that was the authorized heading in the national name authority file at the time of the changeover to the AACR2 rules.

e - Earlier established form of heading (national authority file)

Heading in the 4XX field is a form of the heading in the 1XX field that was formerly established in the relevant national authority file under a situation other than that specified by code a.

o - Earlier established form of heading (other authority file)

Heading in the tracing field is an earlier form of the 1XX heading that was formerly established in an authority file other than the relevant national authority file.

n - Not applicable

Tracing does not contain a formerly established form of the 1XX heading.

/3 - Reference display

One-character alphabetic code that enables the generation or suppression of a cross reference from a 4XX or 5XX field.

a - Reference not displayed

b - Reference not displayed, field 664 used

c - Reference not displayed, field 663 used

d - Reference not displayed, field 665 used

n - Not applicable

COMPLEX CROSS REFERENCE FIELDS

Complex cross references are carried directly in records as reference note fields. The following description is arranged by the source of the reference instruction phrase: tag related (with subfield $i) and subfield $a.