PROPOSAL NO.: 2002-07

DATE: December 18, 2001
REVISED:

NAME: Definition of Additional Second Indicator Values for Specific Subject Systems in Field 655 in the MARC 21 Bibliographic Format

SOURCE: McGill University

SUMMARY: This paper proposes adding second indicator values 0 through 6 to field 655 (Index/Term --Genre/Form) as defined in the 600-651 Subject Added Entry fields in the Bibliographic Format.

KEYWORDS: Field 655 (BD); Index Term - Genre/Form (BD)

RELATED:

STATUS/COMMENTS:

12/18/01 - Made available to the MARC 21 community for discussion.

01/21/02 - Results of the MARC Advisory Committee discussion - Approved.

03/20/02 - Results of LC/NLC review - Approved.


PROPOSAL NO. 2002-07: Definition of Additional Second Indicator Values for Specific Subject Systems in Field 655

1. BACKGROUND

In the Subject Added Entry fields (fields 600 through 651), the second indicator is defined as:

Thesaurus
0 - Library of Congress Subject Headings
1 - LC subject headings for children's literature
2 - Medical Subject Headings
3 - National Agriculture Library subject authority file
4 - Source not specified
5 - Canadian Subject Headings
6 - Répertoire de vedettes-matière
7 - Source specified in subfield $2

In field 655 (Index Term -- Genre/Form), the second indicator is defined as:

Source of term
7 - Source specified in subfield $2

This proposal calls for adding the second indicator values 0-6 in field 655 as they are defined in fields 600 through 651. The existing definition of second indicator value 7 (Source specified in subfield $2) and subfield $2 (Source) will remain as it is at present.

1.1. Implementation of Genre/Form fields in MeSH

The National Library of Medicine has actively implemented bibliographic field 655 for genre terms and the corresponding x55 authority fields. The document, "Conversion Specifications for MeSH to MARC Authority Format," (rev. July 1, 1998) (at www.nlm.nih.gov/mesh/marc99.pdf) describes NLM's use of the authority format as:

"With the 1997 MeSH vocabulary, the 155 field was implemented
for form/genre subject headings. These had previously been included
in field 150."

"With the 1999 MeSH vocabulary, cross-references were introduced
for form/genre subject headings. These are represented in field 455
and 555."

NLM makes a distinction between terms for publication types that are treated as genre terms and those treated as form subdivisions. Those treated as genre terms (e.g. Festschrift, Diaries) are currently coded in field 655 in bibliographic records distributed by NLM:

655 #7 $aFestschrift. $2mesh
655 #7 $aDiaries. $2mesh

1.2 Implementation of Genre/Form fields in LCSH

The implementation of field 655 for genre/form headings in LCSH was discussed following the implementation of subfield $v for form subdivisions, but has yet to take place.

The document "Authority Data Elements Implementation" (07/06/2000) (at: www.loc.gov/catdir/cpso/authimp.html) states the following regarding LCSH usage of x55 fields:

"Authority records for form/genre headings (155). Creation of authority
records for form/genre headings in 155 fields and more widespread
assignment of form/genre terms in 655 fields of bibliographic records
will occur in future stages of the form/genre implementation plan and may
be phased in by format or discipline. The Library is not yet projecting
any specific dates for these future stages of implementation."

2. DISCUSSION

2.1 Field 655

The MARC 21 principles generally encourage the parallel definition of fields in functional blocks. Cataloging training is simplified and accuracy in coding is increased if staff are not required to learn different coding for the same function in different tags. Because field 655 is used in the MeSH subject scheme as part of the complement of subject headings in bibliographic records, catalogers frequently see 655 and 650 fields in the same record and currently must remember to code "MeSH" in two different ways. It may be a simplification for libraries to define field 655 in parallel with the established subject added entry fields. Currently, only catalogers using MeSH according to NLM's cataloging conventions are affected by the difference in coding; however, if LC proceeds with the implementation of field 655 within LCSH, a larger number of catalogers may be affected.

This simplification may also reduce system maintenance overhead. A library that chooses to index subject added entry fields separately by type of thesaurus cannot rely on only the second indicator values if field 655 is involved. To produce a complete MeSH index, the software must be configured to use two different methods to determine the relevant thesaurus depending on which subject added entry field is involved.

Although records already exist using field 655 with second indicator value 7 and subfield $2 (Source) with code "mesh," cataloging agencies may find it desirable to change these records for consistency if this proposal is approved. The amount of legacy data, however, may be substantial for many cataloging agencies, such as the Library of Congress and the National Library of Medicine, have used field 655 extensively with its current indicator value definitions.

2.2 MARC Code Lists for Relators, Sources, Description Conventions

In the section "Term, Name, Title Sources" in the MARC Code Lists for Relators, Sources, Description Conventions, there is a list of term sources appropriate for use in subfield $2 of field 655 and another for subfield $2 of fields 600-651 (Subject Added Entries). Although these two lists may need to remain distinct from each other, the use of subfield $2 source codes for "mesh" and "lcsh" in field 655 may be made redundant with the approval of indicator values for those schemes. The code "mesh" in the field 655 and field 600-651 lists already bears the annotation:

[Used when the second indicator is not adequate to identify the source]

The code "lcsh" has this annotation only in the field 600-651 list and thus, it may need to be added in the field 655 list as well.

3. PROPOSED CHANGES

In the MARC 21 Bibliographic Format:

3.1 Rename second indicator in field 655 to "Thesaurus"

3.2 Define additional values 0 to 6 in field 655 second indicator as follows:

0 - Library of Congress Subject Headings
1 - LC subject headings for children's literature
2 - Medical Subject Headings
3 - National Agriculture Library subject authority file
4 - Source not specified
5 - Canadian Subject Headings
6 - Répertoire de vedettes-matière

In the MARC Code Lists for Relators, Sources, Description Conventions, in the section "Term, Name, Title Sources:"

3.3 In the list of subfield $2 codes valid for field 655, add the notation:

[Used when the second indicator is not adequate to identify the source] to the code: lcsh


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