DATE: Dec. 2, 1994

NAME: Addition of Subfield $b to Field 154 (General Explanatory Index Term) in the USMARC Classification Format

SOURCE: Library of Congress

SUMMARY: This paper proposes the addition of a subfield to field 154 to record a succeeding level or subdivision of a general explanatory index term in the USMARC Classification Format. It is needed for the Library of Congress Classification scheme when a general term refers the user to another term, because there is not one classification number to refer to. It aligns the structure of the field with field 753, which is used for the explanatory note.

KEYWORDS: Field 154 (Classification); Subfield $b, in field 154 (Classification); General Explanatory Index Term (Classification)


12/2/94 - Forwarded to USMARC Advisory Group for discussion at the February 1995 MARBI meetings.

2/4/95 - Results of USMARC Adivsory Group discussion - Approved.

2/16/95 - Results of final LC review - Approved

PROPOSAL NO. 95-5: Addition of Subfield $b to Field 154 
(General Explanatory Index Term)


        The Library of Congress is converting all of the Library of
Congress Classification schedules into the USMARC Classification
Format.  During the development and approval process of this
format, it was not certain which data elements LCC might use.  A
field was developed particularly to accommodate National Library of
Medicine Classification, that it is was also expected would be
applicable for Dewey Decimal Classification, to allow for a general
term that does not point to any particular classification number,
but to other topics.  At the time, it was not expected that LCC
needed this field.

        Index terms (generally, subject terms that are found in the
back-of-the-book index to a classification schedule) are input into
the record for the number to which they refer.  For example, the
index to the H schedule has an entry:
          Building supplies industry: HD9715.9.P56-HD9715.9.P564

The index term is recorded in field 753 (Index Term--Uncontrolled)
in the record that contains HD9715.9.P56-.P64 in field 153.

        There are occasions where there are references in the index to
other terms.  Where possible, that term is recorded in another 753
field of the record in which the referred term appears.  For
example: the following terms are in the H schedule index:
        Multiple employment: see Supplementary employment
        Supplementary employment: HD6490.F6
Both terms are recorded in separate 753 fields in the record for

        Some instances occur where the reference points to another
term that does not refer to one classification number.  It may have
several subtopics under it, or it may point to a general area.  For
instance, the term Automatic data processing has a reference to
Electronic data processing.  Under Electronic data processing are
listed 21 subtopics with their classification numbers, but there is
no general number for Electronic data processing as a whole:
        Automatic data processing, see Electronic data processing
        Electronic data processing
          Advertising:  HF5828.2
          Banking:  HG1709
          Demography:  HB849.5
          Financial management:  HG4012.5
          Industrial relations:  HD6961.2
To include the variant term in field 753 of a classification record
would require that it be repeated in each record with the subtopic. 
Such a practice is redundant and difficult for maintenance. 
Alternatively, field 154 (General Explanatory Index Term) can be
used for this type of situation, or for situations that refer to a
general area.  The record would contain field 154 with the term and
a field 753 with the reference.  The situation above (Automatic
data processing) would be coded as follows:

        154 $aAutomatic data processing
        753 $uElectronic data processing
[753$u is defined as "Use reference term" and could enable a system
to generate a print constant "see".]

        153 $aHF5828.2  [$h hierarchy subfields] $jData processing
        753 $aElectronic data processing $bAdvertising

In the records for each subtopic under Electronic data processing,
there would be a 753$aElectronic data processing with the subtopic
in 753$b, but the general reference from Automatic data processing
would only be in the record for the general index term.

        Although it has not occured frequently, there could be
situations where there is a subtopic under the general explanatory
index term.  It is possible, however, to include subtopics under
the index term in field 753, in subfield $b.  If the term is a
reference and recorded in $u, there is a subfield $v (Use reference
term--succeeding level) in which to record the subtopic.  However,
there is no such subfield in field 154 for a succeeding level.  The
following example is from the KJ-KKZ schedule:
          Criminal justice:  KJA3525
          Higher education:  KJC6314
          Organization, see Organization and administration

While there are 32 subtopics under Administration with
corresponding classification numbers, under Organization and
administration there is no general number.  Currently, there is not
way to consider "Organization" a subtopic under the general term
"Administration".  The coding should be as follows:
        154 $aAdministration $bOrganization
        753 $uOrganization and administration
(The other subtopics in the example above would be recorded in a
753 field in the record for the number to which they refer.)

Such coding allows for the appropriate hierarchical relationships
to be apparent in the index terms and aligns the structure of field
154 with that of field 753.


        The following is presented for consideration:

        -     Add subfield $b (General explanatory index term--
            Succeeding level) in field 154 of the USMARC Classification

        See Attachment A for a description of this field if this
proposal is approved.

                                              ATTACHMENT A

154   General Explanatory Index Term  (NR)


   First                      Undefined

  Second         Undefined

Subfield Codes

    $a     General explanatory index term  (NR)
<   $b     General explanatory index term--Succeeding level  (R)>


       This field contains a general explanatory term from the index
to the classification scheme that is identified in field 084
(Classification Scheme and Edition).  Field 154 is appropriate only
in an index term only record (008/06, Kind of record, code c) that
is created because the index term cannot be accommodated in a 70X-
75X Index Term field in a schedule or table record (008/06, code a
or b) that contains a classification number in field 153
(Classification Number).  This occurs when the index term is not
associated with one classification number or span.  Field 753
(Index Term--Uncontrolled) is always used in a record containing
field 154 to direct the user to different locations within the
classification scheme for classifying the topic.



       Both indicator positions are undefined; each contains a blank


$a - General explanatory index term
       Subfield $a contains a general explanatory index term
       representing a general concept that may be found in numerous
       places in the classification scheme identified in field 084
       (Classification Scheme and Edition).

<$b - General explanatory index term--Succeeding level
       Subfield $b contains a term at a level after the first in a
general explanatory index term.>


       008/06                 c   [index term only record]
       084                    0#$anlm$c4th ed., rev.   [National Library of
                              Medicine Classification]
       154                    ##$aResearch
       753                    ##$i(Form number 20 or 20.5 in any NLM schedule
                              where applicable)
       753                    ##$iOther fields outside the NLM area, in
                              appropriate LC number

       008/06                 c   [index term only record]
       084                    0#$anlm$c4th ed., rev.   [National Library of
                              Medicine Classification]
       154                    ##$aFollow-up studies
       753                    ##$i(Form number 20 in any NLM schedule where
       753                    ##$iIn a particular area, with the subject of
                              the original study, e.g. Heart Diseases,
                              $eWG 200

       008/06                 c   [index term only record]
       084                    0#$addc$bSistema de Clasificación
       154                    ##$aEl
       753                    ##$iv.a. la palabra que sigue al artículo en
                              los nombres geográficos que comienzan con
                              el artículo "el"
                              [Translation of 753: see also the word that
                              follows the article in geographic names that
                              begin with the article "el"]

<      008/06                 c   [index term only record]
       084                    0#$alcc  [Library of Congress Classification]
       154                    ##$aAdministration$bOrganization
       753                    ##$uOrganization and administration>


       008/06                 Kind of record
       084                    Classification Scheme and Edition
       753                    Index Term--Uncontrolled

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