Library of Congress Classification Call numbers (Overview)

For: Technical Services Staff
By: S. Arakawa
Date: (10/10/02/revision date July 7, 2010 1:47 PM )

CONTENTS. General. -- Ex. 1. Single Cutter -- Ex. 2. Double Cuttering with Geographic Cutter -- Ex. 3. Double Cutter with Topical Cutter -- Ex. 4. Decimal expansion & Conference Date -- Ex. 5. Local Geographic Subarrangement -- Ex. 6. Biography Number form Cutter -- Ex. 7. Book Number within a Range -- Ex. 8. Number instead of Cutter -- Ex. 9. Date instead of Cutter -- Ex. 10. Date in class number -- Ex. 11. Date only, no cutter -- Overlaps with non-LC Call Numbers -- Formatting: 050 vs. MFHD -- Transcription -- Local modification -- ClassWeb -- Related Documents


CALL NUMBER: the unique combination of letters and numbers, or just numbers, that indicates the position of the book on the shelf. At Yale, books cataloged before about 1970 have call numbers based on various iterations of the local Yale classification ("Old Yale"). Most books cataloged from 1970 on have call numbers based on the Library of Congress (LC) classification scheme. In most Yale locations, call numbers using LC classification generally are identified by "(LC)" in the last line of the call number.

Call numbers based on LC include both a classification number (class number) and a cutter number. The classification number refers to the subject of the book. If a single cutter number is used, the cutter number refers to the main entry of the work (the author or, if title main entry is used, the title). If there are two cutters, the first cutter is used to bring out a more precise aspect of the subject and the second cutter usually refers to the main entry of the work. (For common exceptions, see Examples 5-7)

LC call numbers generally use a mixed notation of one, two, or three CAPITAL letters, integral or whole numbers from 1 to 9999 with possible decimal extensions, one or two cutter numbers, and, if appropriate, a year of publication.

A single letter, always combined with numbers, represents a main class, corresponding roughly to a broad academic discipline, e.g. N33=general dictionaries of the visual arts.

Double or triple capital letters combined with numbers represent subclasses of the main class, e.g. NB50=dictionaries & encyclopedias of sculpture, i.e., a subclass of the broader visual arts. (In contrast, Old Yale notation may include lower case letters)

On MARC records the LC call number is recorded in the 050 field:

  • LC call numbers assigned by the Library of Congress are tagged as 050 00 or 050 _0.
  • LC classification call numbers assigned by libraries other than the Library of Congress are tagged 050 _4.
  • National Library of Canada call numbers in field 055 are sometimes in synch with LC classification and sometimes not; copy catalogers should not consider them to be equivalent to LC classification call numbers
  • On OCLC records field 090 is sometimes used for recording a locally assigned LC classification call number. CAUTION: A call number appearing in 090 in Voyager is not necessarily LC classification. The call number must be evaluated by the copy cataloger by searching it against the Orbis OPAC in the call number index. If the 090 is judged to be LC classification, it is generally retagged to 050 _4 (if it does not interfere with workflow) in order to facilitate shared cataloging on RLIN. When in doubt, the copy cataloger should check the number on ClassWeb (if authorized) or with a catalog librarian.
  • On RLIN records, call numbers are entered in the CAL/LCAL fields of the record holdings or in the MHO 852. CAL/LCAL will not indicate whether the number is or is not LC classification. MHO 852 1st indicator 0 indicates the number is LC classification.

EXAMPLE 1 (single cutter)

050 0 0 ‡a Z668 b .R365 2000
100 1   ‡a Rehman, Sajjad ur, ‡d 1951-
245 1 0 ‡a Preparing the information professional : ‡b an agenda for the future / ‡c Sajjad ur Rehman.
260     ‡a Westport, Conn. : ‡b Greenwood Press, ‡c 2000.
650   0 ‡a Library education ‡z United States.

Class number: Z668
Cutter number: .R365
Publication date: 2000

For this call number, Z is the main class letter for bibliography and library science. The numbers 668 refer to the subdivision for library education in the United States. Note the correspondence between the class number and the subjects assigned by LC. The second part of the call number, after ‡b, is "cuttered" to Rehman. Note that in the 050 field, the first (or only) cutter is preceded by a period. The third part of the call number is the date of publication.

EXAMPLE 2 (double cuttering with geographic cutter)

050 0 0 ‡a DC611.B848 b H84 1997
100 1   ‡a Hunt, Lindsay.
245 1 0 ‡a Essential Brittany / ‡c by Lindsay Hunt.
260     ‡a Lincolnwood, Ill. : ‡b Passport Books, ‡c c1997.
651   0 ‡a Brittany (France) ‡v Guidebooks.

Analysis of example 2:

DC   The double letters for the subclass, French history
611   The integral number meaning local history and description of an individual region, etc. of France
.B848   The first cutter number for a general work on Brittany. Note that in the 050 field, when double cuttering occurs, the first cutter is separated from the class number by a period; the second cutter is not preceded by a period.
H84   The second cutter number used for the main entry, Hunt
1997   Publication date

EXAMPLE 3 (double cuttering with topical cutter)

050 0 0 ‡a BL65.H36 ‡b F47 1991
100 1   ‡a Ferguson, Harvie.
245 1 0 ‡a Religious transformation in Western society : ‡b the end of happiness / ‡c Harvie Ferguson.
260     ‡a London ; ‡a New York, NY : ‡b Routledge, ‡c 1991.
651   0 ‡a Happiness ‡x Religious aspects.

Analysis of example 3

BL   The double letters for the subclass, Religion, mythology, rationalism.
65   The integral number for Religion in relation to other subjects, A-Z
.H36   The first cutter number for the topic Happiness
F47   The second cutter number used for the main entry, Ferguson
1991   Publication date

EXAMPLE 4 (decimal expansion and conference date):

050 0 0 ‡a PN3433.2 b .S34 1993
110 2   ‡a Science Fiction Research Association. ‡b National Conference ‡d (1993 : ‡c Reno, Nevada)
245 1 0 ‡a Imaginative futures : ‡b proceedings of the 1993 Science Fiction Research Association Conference, June 17-19, 1993, Reno, Nevada / ‡c edited by Milton T. Wolf and Daryl F. Mallett.
260     ‡a San Bernardino, CA : ‡b Angel Enterprises : ‡b Distributed by the Borgo Press, ‡c c1994.
650   0 ‡a Science fiction ‡v Congresses.

Analysis of example 4:

PN   The double letters for the subclass, Literature
3433   The integral number for science fiction
.2   The decimal expansion for congresses
.S34   The cutter for the main entry, Science Fiction Research Association. National Conference ...
1993   The date of the conference <note that the date of the conference differs from the date of publication>

CAUTION. The last cutter's alphabetical letter will not always map to the main entry. Three common types follow.

EXAMPLE 5. (2nd cutter functions as "local" [more specific] geographic subarrangement).


050 0 0 ‡a NA4415.I732 ‡b D835 2000
100 1   ‡a Griffin, David J.
245 1 0 ‡a Leinster House, 1744-2000 : ‡b an architectural history / ‡c David J. Griffin & Caroline Pegum ; [edited by Elizabeth Mayes].
260     ‡a Dublin : ‡b Irish Architectural Archive in association with the Office of Public Works, ‡c 2000.
610 2 0 ‡a Leinster House (Dublin, Ireland) ‡x History.
650   0 ‡a Architecture, Georgian ‡z Ireland ‡z Dublin.
650   0 ‡a Mansions ‡x Remodeling for other use ‡z Ireland ‡z Dublin.
610 2 0 ‡a Ireland. ‡b Oireachtas. ‡b Dâail ‡x Buildings.
650   0 ‡a Dublin (Ireland) ‡x Buildings, structures, etc.


Analysis of example 5. Note that the "base number" cutters are both expanded without using a period.

NA   The double letters for the subclass, Architecture
4415   The integral number for capitol & parliament buildings for "Other countries A-Z"
.I732   The cutter for Ireland ("I73") subdivided locally ("2")
D835   The second cutter for the local subdivision, Dublin, with an additional digit ("5") to account for the main entry (Griffin)
2000   Publication date



EXAMPLE 6. Form cutter. LC uses special tables to deal with common subarrangement patterns.The subarrangements are often form-driven. The LC biography table is a very common application.


050 0 0 ‡a BX4705.N5 ‡b A4 1961
100 1   ‡a Newman, John Henry, ‡d 1801-1890.
245 1 0 ‡a Letters and diaries /‡c edited, with notes and an introduction by Charles Stephen Dessain.
260     ‡a London ; ‡a New York : ‡b T. Nelson, ‡c [1961-<1999>
600 1 0 ‡a Newman, John Henry, ‡d 1801-1890 ‡v Correspondence.
600 1 0 ‡a Newman, John Henry, ‡d 1801-1890 ‡v Diaries.
610 2 0 ‡a Catholic Church ‡z England ‡x Clergy ‡v Correspondence.
610 2 0 ‡a Catholic Church ‡z England ‡x Clergy ‡v Diaries.


Analysis of example 6:

BX   The double letters for the subclass, Religion: Christian Denominations
4705   The integral number for Catholic Church--Individual biography
.N5   The cutter for Newman, John Henry
A4   LC biography table is applied for biography numbers for individuals in all classes unless otherwise instructed in the schedules; the table assigns A4 for collections of letters
1961   Publication date





EXAMPLE 7. Book number is assigned within a number range. Used in literature classification.


050 0 0 ‡a PS3573.I45677 ‡b Z56 2002
245 0 0 ‡a August Wilson : ‡b a casebook / ‡c edited by Marilyn Elkins.
260     ‡a New York : ‡b Garland, ‡c 2002.
600 1 0 ‡a Wilson, August ‡x Criticism and interpretation.
650   0 ‡a Historical drama, American ‡x History and criticism.
650   0 ‡a African Americans in literature.


Analysis of example 7.

PS   The double letters for the subclass, American literature
3573   The integral number for Individual authors, 1961-2000, surnames beginning with "W"
.I45677   The cutter for Wilson, August <cutters to 2nd letter of the surname>
Z56   Second cutter to main entry is assigned within the number range Z4581-Z999 <biography and criticism; table P-PZ40>
2002   Publication date





EXAMPLE 8. Less commonly, a number other than a cutter number is used for subarrangement. Here "14th" refers to the number of the regiment. Note that the non-cutter number is separated by a space rather than a period from the classification number, and that the period precedes the first (and only) cutter number.


050 0 0 ‡a E499.5 14th ‡b .H57 1998
100 1   ‡a Hirst, Benjamin, ‡d 1828-1909.
245 1 4 ‡a The boys from Rockville : ‡b Civil War narratives of Sgt. Benjamin Hirst, Company D, 14th Connecticut Volunteers / ‡c edited, with commentary, by Robert L. Bee.
260     ‡a Knoxville [Tenn.] : ‡b University of Tennessee Press, ‡c c1998.
600 1 0 ‡a Hirst, Benjamin, ‡d 1828-1909 ‡v Correspondence.
610 1 0 ‡a United States. ‡b Army. ‡b Connecticut Infantry Regiment, 14th (1862-1865)



EXAMPLE 9. The other common substitute for a cutter number in LC call numbers is the date. Here "1545" refers to the initial date of the Council of Trent and is preceded by a space rather than a period.

050 0 0 ‡a BX830 1545 ‡b .T45 1997
245 0 2 ‡a I tempi del Concilio : ‡b religione, cultura e societáa nell'Europa tridentina / ‡c a cura di Cesare Mozzarelli e Danilo Zardin.
260     ‡a Roma : ‡b Bulzoni editore, ‡c 1997.
611 2 0 ‡a Council of Trent ‡d (1545-1563) ‡v Congresses.





EXAMPLE 10. Some law class numbers for legislative acts include the date of the act in the class number, in this case 1996. Note that there is no space before the date because the date is considered to be part of the class number. A7 is a form cutter for monographs. The date of publication (2001) is in the standard position.


050 0 0 ‡a KHC3834.51996 ‡b .A7 2001
110 1   ‡a Bolivia.
240 1 0 ‡a Ley del Servicio Nacional de Reforma Agraria
245 1 2 ‡a Ley no. 1715 : ‡b Ley del Servicio Nacional de Reforma Agraria : Reglamento D.S. no. 25763 de 5 de mayo del 2000 ... normas tâecnicas catastrales para el saneamiento de la propiedad agraria.
260     ‡a La Paz : ‡b Instituto Nacional de Reforma Agraria, ‡c 2001.
650   0 ‡a Land reform ‡x Law and legislation ‡z Bolivia.

EXAMPLE 11. A few class numbers do not use cutters; subarrangement is only by date. This pattern is often used with censuses:

050 0 0 ‡a HA851.5 ‡b 2000b
245 0 2 ‡a Censos nacionales : ‡b X de poblaciâon, VI de vivienda, 2000.
260     ‡a [Panama] : ‡b Repâublica de Panamâa, Contralorâia General de la Repâublica, Direcciâon de Estadâistica y Censo, ‡c [2001].
651   0 ‡a Panama ‡v Census, 2000.



CAUTION: some Old Yale class numbers resemble LC class numbers in form but differ from LC in scope, e.g.

Class number LC scope Old Yale scope
B50-B96 Philosophy History of civilization
CE Technical chronology United States history
E United States history Geography
P Languages and literatures Law

As a rule of thumb, even when Old Yale call numbers only use capital letters, they may be identified by their use of lower case letters in some of their cutters and the use of numeric book numbers; also, in most cases Yale adds "(LC)" below the call number for classes that might be mistaken for Old Yale. The number of potentially overlapping situations appears to be quite small. However, since the Voyager call number index in the Orbis OPAC interfiles all classifications, catalogers need to be reasonably alert to the differences when shelflisting. (The interfiling is currently under review.)

LC   Old Yale

A general table for Old Yale numbers is at:

There is also some letter overlap in the SuDoc (U.S. Superintendant of Documents) and LC classes, e.g. TD. SuDoc numbers can usually be identified by the presence of colons and slashes. When viewed in the Voyager Cataloging Module, the 852 first indicator should be 3.

852 3 0 ‡b muddgdcm ‡h TD 4.2:Ai 7/35

The classification scheme selected for the call number must have the correct first indicator in the Voyager MFHD record, or the call number will not index properly. LC classification must have first indicator 0 as in the following example:

852 0 0 ‡b ksl ‡h QC793.5.N42 ‡i N47X 2000 (LC)

Formatting: 050 vs. MFHD

Note that the subfield indicators used to delimit the different parts of the LC call number differ between the 050 on the bibliographic record and the 852 in the MFHD record. Catalogers need to be aware of this when copying and pasting from one field to the other, or when editing a 090 field to 050 _4. (The Voyager ctrl-n command automatically converts the subfield indicators when it copies the call number from 050 or 090 into the MFHD.)

In the bibliographic record's 050 field, the class number is entered in ‡a; the rest of the call number is entered in ‡b when there is a single cutter. If there are 2 cutters, both the class number and the first cutter number are entered in ‡a; the second cutter and the rest of the call number are entered in ‡b.

050 0 0 ‡a NK4165 ‡b .L5 1996

050 0 0 ‡a NK4156.6.A1 ‡b T53 1993

In the MFHD record's 852 field, the class number is entered in ‡h; the rest of the call number is entered in ‡i when there is a single cutter. If there are 2 cutters, both the class number and the first cutter number are entered in ‡h; the second cutter and the rest of the call number are entered in ‡i. Note that the location code is entered in ‡b.

852 0 0 ‡b art ‡h NK4165 ‡i .L5 1996 (LC)

852 0 0 ‡b art ‡h NK4156.6.A1 ‡i T53 1993 (LC) ‡m Oversize

The period used to expand the classification number is REQUIRED in both 050 and 852, e.g.


The period used to separate the cutter number from the classification number is REQUIRED in 050. Note that a period is not entered before the 2nd cutter.

050 0 0 ‡a PN1993.5.I88 ‡b A2 1995

In 852 the period preceding the cutter number may be replaced by a space [a legacy of the previous NOTIS ILS; period is preferred in current Voyager cataloging]. There must be either a space or a period separating the first cutter from the class number to ensure proper indexing.


852 0 0 ‡a sml ‡h PN1993.5.I88 ‡i A2 1995+ ‡m Oversize


852 0 0 ‡a sml ‡h PN1993.5 I88 ‡i A2 1995+ ‡m Oversize


852 0 0 ‡a sml ‡h PN1993.5I88 ‡i A2 1995+ ‡m Oversize

For additional call number formatting examples (852 only), refer to:

Voyager MFHD Examples


At Yale, LC call numbers on labels are arranged vertically to place the class number, each cutter, and the date, on separate lines. Line breaks are not generally made for the integral number following the class letter(s) or the decimal expansion unless the line is unusually long. If the call number is also pencilled on the item, the call number should be transcribed in the same way. Note that the period for decimal expansion is retained but the period before the cutter is optional. The current label printing program prints the period.



Local modification

Some local modification is performed on LC classification call numbers and there is some local deviation from standard LC cuttering practice (currently under review). The modifications and variations are documented in the Modification, Oversize, and Belletristic documents listed below.


The detailed enumeration of the LC classification scheme is published in separate volumes called schedules, e.g. B-BJ. Philosophy-Psychology. The schedules are still not complete (they currently number 40+ volumes and comprise 10,000+ pages; some of the religious law schedules are still only in draft format and unpublished). However, with the publication of the scheme on the web in 2003, catalogers who utilize ClassWeb may find the organization by schedule to be of historical interest only. ClassWeb allows web-based searching of the complete LC scheme, but there is no entry access on ClassWeb via a menu of the schedule organization, the closest being the Subsets limiting page, which is not a web menu, and which only roughly corresponds to the published schedules.

Because the classification scheme is continuously updated, catalogers who assign or check call numbers should always consult ClassWeb rather than the printed schedules or the commercially published cumulations such as Super LCCS to ensure that the most current classification is being assigned to titles new to Orbis.

Related documents:

Outline of LC Classification (requires Adobe software)

Shelflisting introduction


LC Biography Table

LC Cutter Table

Translation table


[TOC] | Cataloging at Yale | [Shelflisting introduction]

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