X50 - Topical Terms-General Information
MARC 21 Authority
October 2009
"Full" documentation refers to the MARC
21 Format for Authority Data that contains detailed
descriptions of every data element, along with examples,
input conventions and history sections.
"Concise" documentation refers to the
MARC 21 Concise Format for Authority Data that
contains abridged descriptions of every data element, along
with examples.
450 - See From Tracing - Topical Term (R)
Full |
Concise
550 - See Also From Tracing - Topical Term
(R)
Full |
Concise
750 - Established Heading Linking Entry - Topical
Term (R)
Full |
Concise
First Indicator
Undefined
# - Undefined
|
Second Indicator
150/450/550 - Undefined
# - Undefined
750 - Thesaurus
0 - Library of Congress Subject Headings
1 - LC subject headings for children's literature
2 - Medical Subject Headings
3 - National Agricultural Library subject authority
file
4 - Source not specified
5 - Canadian Subject Headings
6 - Répertoire de vedettes-matière
7 - Source specified in subfield $2 |
|
|
Subfield Codes
|
Main term portion
$a - Topical term or geographic name entry element (NR)
$b - Topical term following geographic name entry element
(NR)
Tracing and linking subfields
$i - Relationship information (R) [450/550]
$w - Control subfield (NR) [450/550/750]
$0 - Record control number (R) [550/750]
$2 - Source of heading or term (NR) [750]
$4 - Relationship code (R) [450/550]
$5 - Institution to which field applies (R)
[450/550/750]
$6 - Linkage (NR)
$8 - Field link and sequence number (R)
|
Subject subdivision portion
$v - Form subdivision (R)
$x - General subdivision (R)
$y - Chronological subdivision (R)
$z - Geographic subdivision (R)
|
GUIDELINES FOR APPLYING CONTENT DESIGNATORS
Content designators identify the subelements occurring in
topical term and node label headings constructed according to
generally accepted thesaurus-building conventions (e.g.,
Library of Congress Subject Headings). Topical terms
include occupation and function terms that are used as the lead
element of subject or added entry access fields in
bibliographic records. A topical term that is authorized for
use only as a subject subdivision part of an
extended subject heading is contained in a 180 (General
Subdivision) or 182 (Chronological Subdivision) field.
Only generally-applicable content designators are described
in full in this section. A small number of content designators
with field-specific instructions are described in the
Tracings and References-General
Information section (for fields 450 and 550) and the
7XX Heading Linking Entries-General
Information section (for field 750).
■ INDICATORS
First Indicator - Undefined
Undefined and contains a blank (#).
Second Indicator
In fields 150, 450, and 550, the second indicator position
is undefined and contains a blank (#). For field 750, the
second indicator position contains one of the values
described in the
7XX Heading
Linking Entries-General Information section.
■ SUBFIELD CODES
$a - Topical term or geographic name entry
element
Topical subject, a geographic name used as an entry element
for a topical term, or a node label term. Parenthetical
qualifying information is not separately subfield coded.
|
|
|
|
|
|
|
|
|
|
| 150 |
##$aBlood |
| 150 |
##$aCatalogs
by source |
| 150 |
##$aCharacters and characteristics in literature |
| 150 |
##$aBull Run,
2nd Battle of, Va., 1862 |
| 450 |
##$aCaracas.$bBolívar Statue
[Example of a non-LCSH topical see from
tracing.] |
$b - Topical term following geographic name entry
element
Topical term that is entered under a geographic name
contained in subfield $a. This construction is not commonly
used in 150 or 550 heading fields; it may occur in 450 See
From Tracing fields.
|
|
|
|
|
|
|
|
|
|
| 450 |
##$aWashington (D.C.)$bLincoln Memorial |
$i - Relationship information [450/550]
Designation of a relationship of the
entity in a 450 or 550 field to the 1XX entity in the
record or a textual reference instruction phrase than those
that may be system-generated from the field tag or from the
codes defined for subfield $w (Control subfield). Subfield
$i is appropriate only in fields 450 and 550. Guidelines
for using subfield $i are provided in the
Tracings and References-General
Information section.
$v - Form subdivision
Designates a specific kind or genre of material as defined
by the thesaurus being used. Subfield $v is appropriate in
the X50 fields only when a form subject subdivision is
added to a main term to form an extended heading.
|
|
|
|
|
|
|
|
|
|
| 150 |
##$aScuba
diving$vPeriodicals |
$w - Control subfield [450/550/750]
Codes in one or more character positions defined to control
the display of information and specify relationships,
restrictions, and status. Subfield $w is appropriate only
in field 450, 550, and 750. Character position definitions
and guidelines for applying the codes defined for subfield
$w in field 450 and 550 are provided in the Tracings
and References-General Information section. Character
position definitions and guidelines for field 750 are
provided in the 7XX Heading Linking Entries-General
Information section.
$x - General subdivision
Subject subdivision that is not more appropriately
contained in subfield $v (Form subdivision), subfield $y
(Chronological subdivision), and subfield $z (Geographic
subdivision). Subfield $x is appropriate in the X50 fields
only when a general topical subject subdivision is added to
a main term to form an extended heading.
|
|
|
|
|
|
|
|
|
|
| 150 |
##$aConflict
of laws$xSupport (Domestic relations) |
| 150 |
##$aExecutives$xSalaries, etc. |
| 150 |
##$aAmusements$xReligious aspects$xBuddhism,
[Christianity, etc.] |
$y - Chronological subdivision
Subject subdivision that represents a period of time.
Subfield $y is appropriate in the X50 fields only when a
chronological subject subdivision is added to the main term
to form an extended heading.
|
|
|
|
|
|
|
|
|
|
| 150 |
##$aArchitecture, Modern$y19th century |
| 150 |
##$aGod$xHistory of doctrines$yMiddle Ages,
600-1500 |
| 150 |
##$aMusic$y500-1400 |
| 150 |
##$aPainting,
Chinese$ySung-Yüan dynasties, 960-1368$xSocieties,
etc. |
$z - Geographic subdivision
Appropriate in the X50 fields only when a geographic
subject subdivision is added to a main term to form an
extended heading.
|
|
|
|
|
|
|
|
|
|
| 150 |
##$aChapels$zGermany (West) |
| 150 |
##$aWater
resources development$zKenya |
| 150 |
##$aMusic
festivals$zIllinois |
$0 - Record control number
[550/750]
$2 - Source of heading or term
[750]
Code that identifies the source of a heading or term when
the second indicator position contains value 7. Subfield $2
is appropriate only in field 750. Guidelines for applying
subfield $2 are provided in the
7XX Heading Linking Entries-General
Information section.
$4 - Relationship code [450/550]
Contains in coded form the
designation of a
relationship of the entity in a 450 or 550 field to
the 1XX entity in the record. Guidelines for using subfield
$4 are provided in the
Tracings and References-General
Information section.
$5 - Institution to which field
applies[450/550/750]
$8 - Field link and sequence number
INPUT CONVENTIONS
Ambiguous Headings - See Appendix D:
Ambiguous Headings.
Punctuation - Punctuation of the subelements
of a heading is generally dictated by subject heading
system/thesaurus rules. These input conventions clarify MARC
punctuation practices. An X50 field does not end with a mark
of punctuation unless the field ends with an abbreviation, an
initialism, or data that ends with a mark of punctuation.
|
|
|
|
|
|
|
|
|
|
| 150 |
##$aMagazine
illustration |
| 150 |
##$aSeasonal
variations (Economics) |
| 150 |
##$aEducation$zWashington (D.C.) |
| 150 |
##$aMuseums$zRussia (Federation) |
| 150 |
##$aArt,
Chinese$yTo 221 B.C. |
| 150 |
##$aResearch
libraries$zMexico$xSocieties, etc. |
Spacing - No spaces are used in initialisms,
acronyms, or abbreviations.
|
|
|
|
|
|
|
|
|
|
| 150 |
##$aC.O.D.
shipments |
| 450 |
##$aB.A.
degree |
One space is used between preceding and succeeding initials
if an abbreviation consists of more than a single letter.
Display Constant
| - |
[dash
associated with the content of subfield $v, $x, $y, and
$z] |
Dash (-) that precedes a subject subdivision in an
extended subject heading is not carried in the MARC record.
It may be system generated as a display constant associated
with the content of subfield $v, $x, $y, and $z.
|
|
|
|
|
|
|
|
|
|
|
Content designated field:
|
| 150 |
##$aChapels$zGermany |
|
Display example:
|
|
Chapels-Germany
|
CONTENT DESIGNATOR HISTORY
Indicator 2 - Nonfiling characters [150/450/550]
[OBSOLETE, 1993]
Values were: 0-9 (Number of nonfiling characters
present).
$i - Reference instruction phrase
[450/550] [REDEFINED, 2009]
$v - Record control number [750] [REDEFINED, 1995]
[USMARC only]
$0 - Record control number [550/750] [NEW, 1997]
$3 - Authority record control number [OBSOLETE, 1997]
[CAN/MARC only]
$4 - Relationship code [450/550]
[NEW, 2009]