In the MARC 21 Holdings format, a variety of holdings data fields are defined for recording information about the items actually held by a reporting organization. These data elements are divided into the follow four groups where descriptions of specific fields can be found:
A basic bibliographic unit is an entity for which a bibliographic description
exists, for example, a serial, a one-volume book, a multivolume encyclopedia.
This category includes an index or supplementary material for which a separate
bibliographic record exists. The supplementary material and indexes
categories are used for supplementary materials and indexes for which the cataloging
is included in the catalog record for the basic bibliographic unit, that is,
no separate cataloging record exists.
Subfield $8 (Field link and sequence number) is defined to link related
853-878 holdings data fields. Subfield $8 is structured as follows:
[linking number].[sequence number]
Only the linking number portion is used in the Caption and Pattern (853-855) and Textual Holdings (866-868) fields. In Enumeration and Chronology (863-865) and Item Information (876-878) fields, subfield $8 contains both a linking number and a sequence number. The description for subfield $8 is given in the Control Subfields section of this publication, or in Appendix A of the MARC 21 Format for Holdings Data.
When no captions and/or compression or expansion capability for an 863-865 field is desired, the captions and pattern fields are not required in a holdings statement
The 853-855 Captions and Pattern and 863-865 Enumeration and Chronology fields, linked by subfield $8 (Field link and sequence number), are generally used for multipart and serials items when a caption is needed for an intelligible display of the enumeration and chronology data or when publication pattern data is needed to allow the compression or expansion of an 863-865 field by computer algorithm.
Subfield $8 (Field link and sequence number) is defined for the Textual Holdings fields to link the field with the caption and pattern (853-855) and enumeration and chronology (863-865) fields that it replaces or supplements.
The guidelines for applying the content designators and the input conventions for the holdings data fields are given in the following General Information sections: 853-855, 863-865, and 866-868.
Either subfield $3 or subfield $8 is used to link an Item Information field with another holdings field, depending upon which other field is used to record the holdings data. Subfield $3 is used to link to field 852 or 866-868; subfield $8 is used to link to fields 863-866, in which case the enumeration and chronology field must not be compressed beyond the individual physical piece.
A computer algorithm may be used to compress or expand (itemize) the enumeration
and chronology data contained in field 863 (Enumeration/Chronology - Basic Bibliographic
Unit) or in field 864 (for the Enumeration/Chronology - Supplementary Material).
Compression or expansion capability is indicated by the value assigned to the
first indicator position (Compressibility and expandability) in field 853 or
854. Fields 853/863 and 854/864 are linked by the number in subfield $8 (Field
link and sequence number) in each field.
The contents of an 856 enumeration and chronology field for an index may not be compressed or expanded by computer algorithm because an ambiguous holdings string could result. For example, compressed holdings for the first twenty-four volumes of an index that cumulates every fifth volume could be either v. 1-24 or v. 1/5-24. In the second holdings string, the first cumulation is shown but nothing is known about subsequent cumulations. The second indicator position of field 855 (Captions and Pattern--Indexes) is undefined.
Compression means that the content of the enumeration and chronology
subfields ($a-$m) in one or more occurrences of field 863 or 864 can be converted
from an itemized report of a range of holdings to one that expresses the same
holdings in terms of the enumeration or chronology of only the first and last
part held.
Expanded (itemized) holdings:
853 | 20$81 $av. $bno. $u6 $vr $i(year) $j(month) $wm $x01,07 |
863 | 40$81.1 $a113 $i1923 $j01-06 |
863 | 40$81.2 $a114 $i1923 $j07-12 |
863 | 40$81.3 $a115 $b1-2 $i1924 $j01-02 |
863 | 40$81.4 $a115 $b5-6 $i1924 $j05-06 |
[Display example: v.113 (1923:Jan.-Jun.); v. 114 (1923:Jul.-Dec.); v. 115, pt. 1-2 (1924:Jan.-1924:Feb.); v.115, pt.5-6 (1924:May-1924:Jun.)] |
853 | 20$81 $av. $bno. $u6 $vr $i(year) $j(month) $wm $x01,07 |
863 | 30$81.1 $a113-115 $i1923-1924 $j01-06 |
[Display example: v.113-115 (1923:Jan.-1924:Jun.) Holdings Level 3 does not indicate gaps.] |
853 | 20$81 $av. $bno. $u4 $vr $i(year) $j(season) $wq $x21 |
863 | 30$81.1 $a6-7 $i1976-1977 $j21-24 |
863 | 40$81.2 $a8 $b1-3 $i1978 $j21-23 |
[Display example: v.6-8, no.3 (1976-1978:Autumn)] |
853 | 20$81 $av. $bno. $u4 $vr $i(year) $j(season) $wq $x21 |
863 | 40$81.1 $a6 $b1-4 $i1976 $j21-24 |
863 | 40$81.2 $a7 $b1-4 $i1977 $j21-24 |
863 | 40$81.3 $a8 $b1-3 $i1978 $j21-23 |
[Display example: v.6, no.1-4 (1976:Spring-Winter); v.7, no.1-4 (1977:Spring-Winter); v.8, no.1-3 (1978:Spring-Autumn)] |