Structure of the LC Control Number
`Network Development and MARC Standards Office
`Library of Congress
`
`The LC control numbering system has had the same basic structure since its initial use to control Library of
`Congress bibliographic information in card form beginning in 1898 (LCCN structure A). On January 1, 2001, a
`structural change will occur (LCCN structure B). The basic control number has been fixed in length at 12
`characters and will remain that length, although under LCCN structure A suffixes were occasionally used and
`under LCCN structure B the location of element parts is slightly altered to accommodate a four digit year.
`Under both structures, the prefix, year, and serial number are the basic elements required to make a LCCN
`unique.
`
`LCCN Structure A (1898-2000)
`
`Number of characters
`
`3
`2
`6
`1
`variable
`variable
`
`Character position in field
`00-02
`03-04
`05-10
`11
`12-n
`12-n
`
`LCCN Structure B (2001- )
`
`Number of characters
`
`Character position in field
`
`00-01
`02-05
`06-11
`
`Name of Element
`Alphabetic Prefix
`Year
`Serial Number
`Supplement Number
`Suffix / Alphabetic Identifier
`Revision Date
`
`Name of Element
`Alphabetic Prefix
`Year
`Serial Number
`
`2
`4
`6
`
`Alphabetic prefix
`
`Prefixes are carried in a MARC record as lowercase alphabetic characters and serve to differentiate between
`different series of LC control numbers. Prefixes are left justified and unused positions contain blanks. If no
`prefix is present, the prefix portion contains blanks.
`
`Authority Record Prefixes
`
`Google Inc. 1013
`
`0001
`
`0001
`
`

`

`The following alphabetic prefixes have been established by the Library of Congress for Authority records. They
`are used in both LCCN Structures A and B.
`
`MARC
`prefix
`n
`nb
`nr
`
`no
`sh
`sj
`
`sp
`
`Explanation of usage
`
`Name or subject authority record keyed by LC
`Name or subject authority record originating in the British Library
`Name or subject authority record originating in the Research Libraries Information Network
`(RLIN)
`Name or subject authority record originating in the Online Computer Library Center (OCLC)
`LCSH subject authority record distributed by LC
`Juvenile subject authority keyed by LC and distributed in the LC Annotated Children's Cataloging
`Program
`Subject authority proposal record in the LC catalog. (When it is approved, the record will be
`distributed with the prefix sh.)
`
`010 ##$an##79051955#
`[LCCN structure A; number on printed card: n79-51955]
`010 ##$an#2001050268
`[LCCN structure B; number in print form: n2001-50284]
`
`Bibliographic Record Prefixes [Structure A Only]
`
`The following alphabetic prefixes were formally used by the Library of Congress for Bibliographic records.
`Since they were used in records before 2001, they are found in LCCN Structure A only.
`
`Prior to the existence of MARC records, prefixes of various lengths were used on printed cards with
`combinations of uppercase or lowercase letters and numbers. For MARC records, equivalents have been
`defined by the Library of Congress for some of these early prefixes. The second column in the list below gives
`prefixes found on printed cards not printed from machine-readable records and shows how they are to be input
`into a MARC version of the record. Only card prefixes which have a MARC form noted below should be
`recorded in machine-readable records.
`
`MARC
`Prefix
`
`a
`ac
`
`ac
`af
`
`Prefix
`on
`card
`A
`AC
`
`AC
`AF
`
`Explanation of usage
`
`Cataloging provided to LC by an American library, 1909-
`Cataloging for foreign materials provided to LC by cooperating libraries under the auspices
`of the ALA Committee on Cooperative Cataloging, 1932-1942
`Annotated cards for juvenile books, 1966-
`Cataloging for foreign acquisitions provided to LC by other American libraries, 1946-1950.
`
`0002
`
`0002
`
`

`

`afl
`agr
`bi
`br
`bs
`c
`c
`c
`
`ca
`cad
`
`cd
`cd
`clc
`cs
`
`cx
`cy
`d
`
`do
`e
`es
`f
`f
`
`fi
`fia
`fie
`
`g
`
`CX
`
`1-D-
`245
`or D-
`245
`DO
`E
`ES
`F
`1-F-
`245
`or F-
`245
`Fi
`FiA
`FiE
`
`1-G-
`245
`
`AFLM No explanation available
`Agr
`U.S. Department of Agriculture cataloging, 1902-
`
`Handbook of Latin American Studies record
`BR
`Library of Congress, Division for the Blind, Braille book
`BS
`U.S. Bureau of Standards cataloging, 1913-1938.
`C
`U.S. Interstate Commerce Commission cataloging, 1915-1916
`C
`Library of Congress, Chinese entries, 1949-
`C-245
`LC card numbers for June-August 1898. Year prefix "98" added when input into MARC
`or 245
`CA
`CA
`Dupl
`CD
`CD
`
`CS
`
`LC temporary entries for books in the general classified collections, 1905-1937
`LC temporary entries for books in the general classified collections, 1905-1937
`
`LC analytical entries for sets and series prepared by the Card Division, 1916-1940
`Cataloging prepared for LC card sales
`Collection level cataloging; PREMARC record
`Cataloging prepared by the LC Cooperative Cataloging and Classification Service, 1934-
`1939
`Cross reference cards used in LC catalogs for Chinese entries, 1958-
`Federal Cylinder Project, Oct. 1980
`LC card numbers for May-December 1901. Year prefix "01" added when input into
`MARC
`
`U.S. Superintendent of Docs. cataloging, 1913-1916
`U.S. Office of Education cataloging, 1908-1958
`U.S. Engineers School cataloging, 1913-1935
`U.S. Bureau of Fisheries cataloging, 1910-1940
`LC card numbers for May-December 1901. Year prefix "01" added when input into
`MARC
`
`Films cataloged by LC, 1951-
`Cataloging provided by film producers, 1951-
`Cataloging provided by the Visual Education Service of the Office of Education, and other
`government agencies, 1951-
`LC card numbers for May-December 1901. Year prefix "01" added when input into
`MARC
`
`0003
`
`0003
`
`

`

`gm
`gs
`h
`ha
`he
`hew
`hex
`it
`
`or G-
`245
`Maps cataloged by LC, 1968-1972
`GM
`U.S. Geological Survey cataloging, 1904-
`GS
`U.S. National Institute of Health cataloging, 1914-1921
`H
`U.S. Housing Authority cataloging, 1940-
`HA
`Hebrew entries cataloged by LC, 1964-
`HE
`HEW U.S. Dept. of Health, Ed., and Welfare cataloging, 1958-
`HEX
`Cross reference cards used for Hebrew entries, 1964-
`1-I-245
`LC card numbers for May-December 1901. Year prefix "01" added when input into
`or It-
`MARC
`245
`Int
`int
`J
`j
`JA
`ja
`JX
`jx
`K
`k
`KX
`kx
`L
`l
`
`llh
`
`ltf
`M
`m
`MA
`ma
`map Map
`map
`1-Map-
`50
`or
`Map-
`50
`U.S. Armed Forces Medical Library cataloging, 1946-1948
`med Med
`Microfilms cataloged by LC, 1949-
`mic
`Mic
`mid
`MicA Microfilms for which cataloging was provided by another American library, 1946-
`
`U.S. Department of the Interior cataloging, 1959
`LC cataloging for Japanese materials 1949-
`Cataloging for Japanese materials provided to LC by other American libraries, 1951
`Cross reference cards used for Japanese entries, 1958-
`Korean entries cataloged by LC, 1951-
`Cross reference cards used for Korean entries, 1958-
`U.S. Dept. of Labor cataloging, 1911-
`Index to Hispanic Legislation cataloging
`Less-than-full cataloging; PREMARC record
`Sheet music cataloged by LC, 1953-1962
`Sheet music for which copy was supplied by another American library, 1953-1961
`Atlases in the Maps Division of LC, 1901-
`LC card numbers for maps for period May-December 1901. Year prefix "01" added when
`input into MARC
`
`mie
`mif
`
`mm
`
`Micp Microcards and microprints cataloged by LC, 1953-
`MicpA Microcards and microprints for which cataloging was provided by another American library,
`1953-
`Library of Congress Manuscript Division
`
`
`
`0004
`
`0004
`
`

`

`Early films cataloged by LC, 1970s
`
`mp
`mpa MPA Pan American Union cataloging for sheet music, 1956-
`ms
`MS
`Manuscripts cataloged by LC, 1959-
`mus
`1-
`LC card numbers for music for May-December 1901. Year prefix "01" added when input
`Music-
`into MARC
`245
`or
`Music-
`245
`Nitrate Film Service cataloging
`
`Materials published in the Near East or in the languages of those countries, 1961-
`NE
`NEX Cross reference cards used for books published in the Near East or in the languages of
`those countries, 1961-
`U.S. Naval Observatory cataloging, 1930-1940
`NO
`National Translation Center cataloging
`
`Records printed in the National Union Catalog for which no LC card number is available
`
`Order Division cataloging
`
`Pan American Union cataloging, 1930-
`PA
`Cataloging provided by other libraries for photographic reproductions of books, 1927-
`Pho
`PhoM Cataloging provided by Card Division for photographic facsimiles issued by the Modern
`Language Association of America, 1927-1938
`PhomA Cataloging provided by other libraries for Modern Language Association of America
`photographic facsimiles
`U.S. Patent Office cataloging, 1917-1953
`Prints and Photographs videodisc system, March 1984
`Photograph records cataloged by LC, 1953-
`Cataloging provided by other American libraries for photographs, 1955-
`LC card numbers for May-December 1901. Year prefix "01" added when input into
`MARC
`
`ncn
`ne
`nex
`
`no
`ntc
`nuc
`or
`pa
`pho
`php
`
`phq
`
`po
`pp
`r
`ra
`rc
`
`PO
`
`R
`RA
`1-Rc-
`245
`or Rc-
`245
`
`re
`ru
`s
`sa
`
`
`
`S
`SA
`
`sax
`
`SAX
`
`Cataloging for commercial ethnic sound recordings produced in the U.S. project, 1981
`Cataloging from the Russian Book Chamber, 1988-
`Smithsonian Institution cataloging, 1913-
`Cataloging for materials published in Southeast Asia or in the languages of those countries,
`1961-
`Cross reference cards used for materials published in Southeast Asia or in the languages of
`those countries, 1961-
`
`0005
`
`0005
`
`

`

`Serials, CONSER item not in LC
`U.S. Dept. of State cataloging, 1914-
`Serials form card or Minimal Level Cataloging or classed separately monographic series
`Surgeon General's Library, U.S. Army cataloging, 1916-
`Serials, CONSER, item may or may not be in LC
`Social Security Administration cataloging, 1944-1958
`Split manuscript records
`Talking Books program cataloging
`Temporary cataloging from PREMARC
`Union map; an outside map record input by the Geography and Map Division for NUC use
`but residing in the G&M database
`Card for which no LC card number was available; PREMARC
`District of Columbia Public Library cataloging, 1905-1942
`U.S. Army, War College cataloging, 1907-1932
`Cross reference cards used in LC catalogs, January 1941-
`LC card numbers for May-December 1901. Year prefix "01" added when input into
`MARC
`
`sc
`sd
`sf
`sg
`sn
`ss
`su
`tb
`tmp
`um
`
`
`SD
`
`SG
`
`SS
`
`TB
`
`
`
`
`unk
`W
`w
`war War
`x
`X
`z
`1-Z-
`245
`or Z-
`245
`
`010 ##$a###68004897#
` [LCCN structure A; number on printed card: 68-4897]
`010 ##$a##2001045944
` [LCCN structure B; number in print form: 2001-45944]
`
`Classification Record Prefixes
`The following alphabetic prefixes have been established by the Library of Congress for Classification records.
`They are used in both LCCN Structures A and B.
`
`MARC prefix:
`cf
`ct
`
`Explanation of usage
`Classification record keyed by LC
`Table record keyed by LC
`
`010 ##$acf#97051955#
` [LCCN structure A; number on printed card: cf97-51955]
`010 ##$acf2001050268
` [LCCN structure B; number in print form: cf2001-50268]
`
`0006
`
`0006
`
`

`

`Holdings and Community Information Record Prefixes
`The alphabetic prefix portion contains blanks.
`
`Year
`
`Authority Records
`For control numbers assigned under LCCN structure A, the year portion consists of two digits representing the
`year the control number was assigned. In name authority records that were converted retrospectively by an
`agency under contract to LC, the digits 50 were used for the year for name authority records, and the digits 42
`were used for series authority records. In subject authority records that were converted retrospectively from an
`LC internal format to MARC, the digits 85 were used instead of the actual year of creation.
`
`For control numbers assigned under the LCCN structure B beginning with the year 2001, the year portion
`consists of four digits.
`
`Bibliographic Records
`For control numbers assigned under LCCN structure A, the year portion consists of two digits representing the
`year the control number was assigned. In most numbers, the year portion reflects the year in which the LC
`control number was assigned to the record for the bibliographic item. During the 1969-1972 period, a 7-series
`year number was assigned. In these numbers the initial digit of 7 was followed by a modulus-ll check digit. The
`year in which the card number was assigned can be approximated from the year portion of the Date entered on
`file (008/00-05). With the re-institution of the year series number in 1972, provisions were made to skip those
`individual card numbers which could have been assigned previously as a 7-series number. Note: 7-series
`numbers were not used for non-book map material. The prefix gm was used from 1968 through 1972.
`
`For control numbers assigned under the LCCN structure B beginning with the year 2001, the year portion
`consists of four digits.
`
`For LC control numbers with two-digit years, the century may be determined according to the following table:
`
`2-digit year
`98
`99
`00
`
`Sequential number
`Less than 3000
`Less than 6000
`Less than 8000
`
`Century
`18
`18
`19
`
`Sequential number
`3000 or greater
`6000 or greater
`8000 or greater
`
`Century
`19
`19
`20
`
`Classification, Holdings and Community Information Records
`For control numbers assigned under LCCN structure A, the year portion consists of two digits normally
`representing the year the record was created.
`
`For control numbers assigned under LCCN structure B beginning with the year 2001, the year portion consists
`of four digits.
`
`Serial number (All Formats)
`
`0007
`
`0007
`
`

`

`The serial number portion consists of one to six digits. Serial numbers of less than six digits are right justified and
`unused positions contain zeros. The hyphen which separates the year and the serial number on LC displays and
`printed products is not carried in the MARC record. For example, the number 85-2 is carried as 85000002 in
`a record.
`
`Supplement number (All Formats) [Structure A Only]
`
`This character position was originally defined to carry a supplement number for dashed-on supplement entries in
`bibliographic records. Use of the supplement number was not implemented for bibliographic, authority,
`classification, holdings and community information records, therefore this position contains a blank in all LCCN
`Structure A identifiers.
`
`Suffix/Alphabetic Identifier (Bibliographic Records only) [Structure A Only]
`
`Older LC control numbers sometimes include suffixes or alphabetic identifiers carried as variable length data
`following the Supplement number. A single slash (/) introduces the suffix/alphabetic identifier. Multiple
`occurrences of either suffixes or alphabetic identifiers are separated one from the other by a slash. Suffixes and
`alphabetic identifiers do not affect the uniqueness of the control number.
`
`All suffixes and alphabetic identifiers, except the revision date, appear in the MARC record as uppercase
`alphabetic characters. On printed card copy, suffixes appear after the LC control number separated by a slash.
`Suffixes have not been assigned since 1969 and they will be deleted from Library of Congress files in 1999.
`Alphabetic identifiers appear on printed card copy as uppercase alphabetic characters beneath the LC card
`number in the lower right hand corner of the card. Alphabetic identifiers were first assigned in 1969 and were
`used as distribution information for card copy by LC. Alphabetic identifiers were deleted from the Library of
`Congress files in 1999.
`
`010 ##$a###79139101#/AC/MN
` [Printed number is 79-139101 with AC MN printed below the number.]
`010 ##$a###65077628#/MN
` [Printed number is 65-77628 with MN printed below the number.]
`
`Suffix/alphabetic identifiers
`
`AC used on records included in the "Annotated Card" program
`AM used for works in Amharic
`ACN used for works in Chinese
`AJ
`used for works in Japanese
`AK used for works in Korean
`used for records created by the Audiovisual Section, Special Materials Cataloging Division for motion
`pictures, filmstrips, sets of slides and transparencies, video recordings, etc.
`
`F
`
`0008
`
`0008
`
`

`

`HE used for works published in the Hebrew alphabet, regardless of language
`M used for works classed in M
`MAP used for atlases
`MN used for works classed in ML and MT
`MP used for records created by the Motion Picture, Broadcasting and Recorded Sound Division
`NE used for works in Armenian, Arabic, Georgian, Ottoman Turkish, Persian, Pashto, and Turkish, as well
`as any non-Slavic language of Central Asia written in the Cyrillic alphabet
`PP
`used for records created by the Prints and Photographs Division
`R
`used for all sound recordings
`
`Revision Date (Bibliographic Records only) [Structure A Only]
`
`The revision date associated with LC control numbers specified the latest date that the bibliographic data in a
`record underwent a change. Revision data do not affect the uniqueness of the control number. To account for
`the number of times significant changes have been made to a record beyond the first such change, a number was
`added as the last character of the revision date. The date a record was originally created is the Date entered on
`file (field 008/00-05).
`
`A revision date such as "r73" means that the record was changed in 1973. The revision date "r743" means
`that significant changes have been made to the record three times, the last being made in 1974.
`
`010 ##$a###75425165#//r75
` [Number 75-425165 revised in 1975.]
`
`010 ##$a###73002284#//r752
` [Number 73-2284 with [r75]rev 2 printed revision information.]
`
`010 ##$a###58062665#/L/r58
`[Printed number is 58-62665 rev. (The * was represented on the printed product by a double
`dagger and indicates limited cataloging; it was carried in the MARC record as an L. When the
`LC control number was printed from the MARC record, the L printed as Lim beneath the
`control number.]
`
`
`
`The revision date was used as an indication of the degree of importance of a change made to a record. A
`significant change to a record at the Library of Congress was defined as one important enough to warrant,
`among other things, redistribution of cards to LC's own catalogs. A significant change included changes to
`content designation, to an access point (fields 020, $a or $z, 028, $a, 050, 051, 082, 1XX, 240, 245 #a, 4XX
`(excluding 490), 6XX, 7XX, 8XX), a change to the extent of an item (300 #a), a change to the publication date
`(260 #c), a change to the record control number (field 001), or a change to Leader/18 (Descriptive cataloging
`form).
`
`0009
`
`0009
`
`

`

`Revision information was separated from a suffix or an alphabetic identifier by one slash (/). If no suffixes or
`alphabetic identifiers are present, revision information was separated from the Supplement number by two
`slashes (//). The inclusion of revision data was discontinued in 1999 and deleted from all records in the Library
`of Congress files.
`
`Go to:
`
`MARC Standards Home Page
`Library of Congress Home Page
`
` Library of Congress
`Library of Congress Help Desk ( 06/16/2006 )
`
`0010
`
`0010
`
`