PROPOSAL NO.: 2004-02

DATE: December 10, 2003
REVISED:

NAME: Defining New Field Link Type Codes for Subfield $8 (Field link and sequence number) in the MARC 21 Bibliographic and Holdings Formats.

SOURCE: RLG

SUMMARY: This paper proposes defining new link type codes "a" (action) and "x" (general sequencing) in subfield $8. This will facilitate linking between field 583 (Action note) and specific note fields 541 (Immediate Source of Acquisition Note) and 561 (Ownership and Custodial History).

KEYWORDS: : Field link type (BD, HD); Field 541 (BD, HD); Field 561 (BD, HD); Field 583 (BD, HD); Immediate source of acquisition note (BD, HD); Action note (BD, HD); Subfield $8 (BD, HD); Ownership and custodial history (BD, HD)

RELATED: Proposal 95-6 (December, 1994); Proposal 98-2 (November, 1997); Discussion Paper DP101 (May, 1997)

STATUS/COMMENTS:

12/10/03 - Made available to the MARC 21 community for discussion.

01/10/04 - Results of the MARC Advisory Committee discussion - Approved as amended. Specific references to fields 541, 561 and 583 in the link type code definitions will be removed in the documentation.

03/18/04 - Results of LC/NLC/BL review - Agreed with the MARBI decisions.

Proposal 2004-02: Defining New Field Link Type Codes for Subfield $8

1. BACKGROUND

Subfield $8 may be used to link related fields within a single record. The MARC 21 bibliographic and holdings formats provide a link type code to explain how the linked fields are related. Subfield $8 is defined as followed:

$8 – Field Link and Sequence Number

Subfield $8 contains data that identifies linked fields and may also propose a sequence for the linked fields. Subfield $8 may be repeated to link a field to another field or a group of fields. The structure and syntax for the field link and sequence number subfield is:

$8<linking number>.<sequence number>\<field link type>

The linking number is the first data element in the subfield and required if the subfield is used. It is a variable-length whole number that occurs in subfield $8 in all fields that are to be linked. Fields with the same linking number are considered linked.

The sequence number is separated from the linking number by a period "." and is optional. It is a variable-length whole number that may be used to indicate the relative order for display of the linked fields (lower sequence numbers displaying before higher ones). If it is used it must occur in all $8 subfields containing the same linking number.

The field link type is separated from preceding data by a reverse slash "\". It is a code indicating the reason for the link and it follows the link number, or sequence number if present. Field link type is required except when $8 is used to link and sequence 85X-87X holdings fields. The following one-character field link type codes have been defined in MARC for use in subfield $8:

c - Constituent item
Code c is used in a record for a collection, or a single item consisting of identifiable constituent units, to link the fields relating to the constituent units. All other non-linked data elements in the record pertain to the collection or item as a whole.

r - Reproduction
Code r is used in a record for a reproduction to identify fields linked because they contain information concerning only the reproduction. Other descriptive information in the record pertains to the original (with the exception of field 007 (Physical Description Fixed Field), 008 (Fixed-Length Data Elements: Books, Music, Serials, or Mixed Material) position 23 (Form of item), field 245 subfield $h (Title Statement / Medium), and field 533 (Reproduction Note)).

Linking Action and acquisition fields. For many years, RLG has recognized that a link may exist between data in fields 541 (Immediate Source of Acquisition Note), and 583 (Action Note) when the actions described in the 583 fields relate to the same item described in the 541 field. Up to now, RLG has represented that link using local elements. However, RLG is moving to a new database environment in the near future and would like to convert its local elements to MARC 21-defined subfield $8 elements. This will allow RLG to provide standard MARC 21 export to its users. It is possible that a similar link may exist between the 583 (Action Note) and the 561 (Ownership and Custodial History) field, so it seems useful to include it in this proposal.

Linking fields for display sequencing. There may be a need for an additional field link type code. A general principle of MARC record processing that is preferred by MARC users is to keep fields within a defined block in source order so that the relative importance of 5XX notes or fields in other blocks is maintained. Although some processing agencies do this, other agencies output fields in numeric tag order instead. The inputting agency’s original sequencing of fields within a block could be guaranteed (when important) by using subfield $8.

2. DISCUSSION

2.1 Action and acquisition related fields

A bibliographic record may contain one or more 541 or 561 fields for data about the immediate source of acquisition of the item or collection described in the record. A 541 field may contain data about the complete item or collection described in the record, or may contain data about only part of the item or collection. The 561 field may contain data about information concerning the ownership and custodial history of the described materials from the time of their creation to the time of their accessioning. Both the 541 and 561 fields are repeatable so that unique data that pertains to the acquisition of additional parts of a collection may be recorded.

A bibliographic record may contain one or more 583 fields for data about processing or reference actions taken for the item or collection described in the record. Like the 541 or 561 fields, the data in the 583 field may describe action taken for the complete item or collection described in the record, or just part of the item or collection. Because more than one action may be taken for the item or collection, or some part of it, the 583 field is repeatable to record unique data pertaining to a particular action.

There is a need to link 541, 561 and 583 fields when there is more than one 541 or 561 field in a record and there are 583 fields that relate to a particular 541 or 561 field. Although the processing or reference actions are described fully in the 583 fields, they are meaningful only in relation to a specific 541 or 561 field. For example, if a record that describes the reports of a state agency has 541 fields that show acquisition of various parts at different times, various actions may be recorded in 583 fields that pertain to a particular 541 field.

Although the order of fields in a record can show the relationship of 541 or 561 and 583 fields, it is preferable to have an explicit statement of linked fields so that if the record is processed in a way that disrupts the source order, the related fields can still be identified. This would permit the proper order to be reestablished, either "physically" in the record, or "virtually" for display. Subfield $8 linking in the example in section 2.1.1 would make the relationship of 541 or 561 and 583 fields clear.

Further, a 583 field may not necessarily relate to a particular 541 field in a record. Here there would be a link from the last 583 field to the last 541 field in the record, but the other 583 and 541 field would have no link stated. That would make it clear that the first 583 field related to the entire collection described in the record (as of the action date), and that no field 583 actions were related to the first 541. For example:

It is true that subfield $3 can show a relationship between fields 541, 561 and 583, but it may not be used in some cases. Accession numbers (field 541 subfield $e and field 583 subfield $b) can also show a relationship between those two fields, but again they may not necessarily be used. Even if subfield $3 or the accession number subfields are present in both fields 541 and 583, it is easier for a machine to order or provide display fields based on subfield $8 than by using the contents of subfield $3 or other subfields. Subfield $8 is the appropriate mechanism to make a link between fields and express its nature. In the case of fields 541, 561 and 583, the link is between 583 fields that describe processing or reference actions that relate to the same 541 or 561 field.

The use of subfield $8 with 541 or 561 and 583 would be optional. In many cases, there is no need to link the fields because there is only one 541 or 561 field in the record and all 583 fields relate to it. When it was used, however, a machine could determine when a 541 or 561 field and one or more 583 fields were related. The machine could also determine when some 541 or 561 and 583 fields were not related to other 541or 561 and 583 fields in the record.

2.1.1 Examples

2.2 General sequence relationship

One part of subfield $8 is the sequence number. Its use is optional, but when present it can be used to order fields for display or other purposes. In some cases, it is important that a group of fields is kept in a particular order, whether to show relative importance of the fields within the group, or some other relationship between them. Many MARC record processing agencies have the ability to maintain source order of fields. However, not all have, or consistently exercise, that ability. In that case, without specific marking of the sequence between related fields, the sequence relationship can be lost.

Some bibliographic databases have limits on the size of fields, sometimes well below the 9999 byte limit of a MARC 21 record directory entry. This may force users of such databases to break long fields such as 5XX notes into pieces. Having a mechanism to establish the sequence of the pieces can be useful if there is the potential that the pieces might not be kept in proper order by some MARC record processor.

To cope with the cases above, it seems useful to define a general subfield $8 link for a sequencing relationship between fields. Such a definition would allow for a variety of uses. There seem to be at least two options. First, a new field link type code could be defined for "general sequencing" relation between fields. This method is proposed in this paper. Alternatively, the field link type code could be left out of subfield $8 when a general sequencing relation occurs between fields. However, if the type code does not appear in subfield $8, it is not clear whether it was left off by accident or to show the sequencing relationship. It might be clearer to define a new field link type code for the sequencing relationship, so that alternative option is not presented in the proposed changes below.

2.2.1 Example

3. PROPOSED CHANGES:

In the MARC 21 bibliographic format:

Define the following field link type codes for subfield $8:

a - Action
Code a is used in a record to link one or more 583 fields with the 541 or 561 field to which the processing or reference actions relate. This code is typically used only when there is more than one 541 or 561 field in a record and there are one or more 583 fields that relate to a particular 541 or 561 field.

x - General sequencing
Code x is used in a record to make a link between fields to show a sequence between them. The sequence could be one that orders the pieces of a long field that has been broken up, indicates the relative importance of fields within the sequence, or is used for some other sequencing purpose. Use of the sequence number in $8 is required when this code is used.

• List of Proposals
• MARC Home Page
• Library of Congress Home Page