76X-78X - Linking Entry Fields

Fields 760-78X contain information that identifies other related bibliographic items. Each of the linking entry fields specifies a different relationship between the target item described in the record and a related item. These relationships fall into three categories: 1) related items that assist the user in continuing to search but are not physically required to obtain the target item (e.g., former entries for serials, translations of the target item); 2) related items that have to be obtained physically in order to use the target item (e.g., the host item for a component part: a journal issue containing a specific article); 3) related items that are constituent units of a larger whole (e.g., the individual photographs contained in a visual material collection). The linking entry fields are intended to generate a note in a display of the record in which they appear; provide machine linkage between the bibliographic record for the target item and the bibliographic record for the related item, if the related item is covered by a separate record; and/or facilitate indexing.

[Additional fields in MARC 21 Concise Formats]

Definitions of terms used in the Linking Entry fields:

Target item

a bibliographic item that is the principal or primary unit for the description of which the record was constructed. The target item is the item to which the data in Leader/06 (Type of record) and /07 (Bibliographic level) apply. The title of the target item is in the record's 245 field.

Related item

a bibliographic item that has either a chronological, horizontal, or vertical relationship with a target item, and for which the linking entry field is formulated.

Component part

a bibliographic item that is physically part of another bibliographic item such that the retrieval of the part is dependent on the physical identification and location of the host item (e.g., a chapter in a book, an article in a journal). (Field 774)

Constituent unit

a bibliographic item that is part of another item. The constituent unit is physically separate from the item of which it is consider a part. (Fields 770, 774)

Host item

a bibliographic item that either physically contains (as in the case of the component part), or bibliographically includes, (as in the case of a constituent unit), the subpart that is the target item for the record. For example: if a record describes a journal article, the host is the journal; if a record describes one digital item in a set, the host is the set. (Fields 772, 773)

Chronological relationship

the relationship in time between bibliographic items (e.g., the relation of a serial to its predecessors and successors). (Fields 777, 780, 785)

Horizontal relationship

the relationship between versions of a bibliographic item in different languages, format, media, etc. (Fields 765, 767, 775, 776)

Vertical relationship

the hierarchical relationship of the whole to its parts and the parts to the whole (e.g., a journal article to the journal, subseries to main entry series). (Fields 760, 762, 770, 772, 773, 774)

The record-linking technique in MARC is described below.

Linking Entry Fields (fields 760-787)

These fields carry descriptive data concerning the related item, the control number for the record of the related item, or both. Minimal content designation is provided for the data concerning the related item that is used in the linking entry fields. For data operations requiring fuller content designation, such as indexing and sorting, subfield $w (the record control number for the related item) allows the system to follow that link to the related record to obtain fully content-designated data.

Added Entries (fields 700-730)

When a cataloging code calls for an added entry for a title used in a linking field, the added entry is recorded in the appropriate 700-730 field. Linking fields are not intended take the place of added entries. Likewise, an added entry in field 700-730 does not take the place of a linking field, as it cannot cause a note to be generated or carry a record link.

Component Parts/Constituent Units

The linking entry field 773 (Host Item Entry) is used to link a target item that is an integral (component) part of another item to the record for the other item. For example, in records for journal articles it contains the identification of the journal. In subfield $g of field 773, the exact location of the article in the journal is recorded. The record for the host item or any larger bibliographic unit may include information about constituent units, recorded in the repeatable field 774 (Constituent Unit Entry). Information about each constituent would be recorded in a separate occurrence of field 774.