1 Introduction

Chapter Summary

1.1 Machine-Readable Bibliographic Records
1.2 Bibliographic Formats
1.3 WorldCat Bibliographic Records
1.4 Information in Bibliographic Records
1.5 Offline Cataloging Products

Bibliographic Formats and Standards is a guide to the bibliographic information on records in WorldCat®. It provides tagging conventions, input standards and guidelines for entering information.

WorldCat is a database of cataloging and classification information. Records are machine-readable bibliographic descriptions of items held by OCLC member institutions. The system links each bibliographic record to locations information.

During the cataloging process, institutions create bibliographic records for items or add their OCLC symbol to existing records.

Members catalog library materials according to the current revision/update of Anglo-American Cataloguing Rules, second edition (AACR2), and its amendments, published by the American Library Association (ALA). They can catalog all types of library materials in languages that use the Roman alphabet and those that use Arabic, Chinese, Devanagari, Japanese, Korean, Hebrew, Cyrillic, Greek, Tamil, and Thai characters.

Members may also enter pre-AACR2 cataloging copy during retrospective conversion.

Members may enter records according to Dublin Core (DC) practices. These records will not conform to AACR2. For more information, see the Connexion documentation (http://www.oclc.org/support/documentation/connexion/).

1.1 Machine-Readable Bibliographic Records


A machine-readable (MARC) bibliographic record consists of fields. A field is an area in which the same kind of bibliographic information is consistently entered. MARC bibliographic records in WorldCat have two kinds of fields:

  • One fixed field for coded information that facilitates retrieval and data manipulation and
  • Multiple variable fields for textual information


MARC 21 is the technical standard for the encoding of bibliographic information. It is maintained by the Library of Congress. OCLC-MARC is OCLC's implementation of MARC 21. While OCLC-MARC follows MARC 21 closely, there are differences, many of which are noted in this manual. See also MARC 21 Bibliographic Data Elements not Implemented by OCLC (http://www.oclc.org/support/documentation/worldcat/records/notimplemented/default.htm).

Fixed field

An OCLC-MARC record has one fixed field composed of the 008 field and Leader information. Mnemonic labels identify elements that contain coded information describing the item and the record itself. For more information, see OCLC-MARC Records (http://www.oclc.org/support/documentation/worldcat/records/subscription/).

Variable fields

The remaining fields in MARC records are variable in length and number. Each variable field may have from 1 to 9,999 characters. MARC variable fields have three parts:

  • A three-digit tag
  • Up to two single-digit indicators
  • One or more subfields


MARC tags identify variable fields and are grouped numerically by function. In the following list, xx stands for a numeric value between 00 and 99:

Tag Group Function
0xx Bibliographic control numbers and coded information
1xx Main entries
2xx Titles, edition and imprint information, etc.
3xx Physical description, etc.
4xx Series statements
5xx Notes
6xx Subject access entries
7xx Added entries other than subject or series and linking fields
8xx Series added entries and holdings
9xx Local use fields


In MARC records, indicators supply information about the field for indexing, card production or other system functions. Numbers in the indicator positions have assigned meanings and in some fields, a blank space is meaningful. Variable field indicators may have:

  • A number in both positions
  • A number in one position and a blank space in the other
  • Two blank spaces


Subfields are the smallest logical unit of information in a variable field. Subfield codes (letters or numbers) identify subfields and are preceded by subfield delimiters (‡). In Connexion browser, the subfield delimiter displays as a dollar sign ($).

Subfields usually contain the textual information for the bibliographic description of the item, although in some cases they contain coded information. (Subfield ‡a is implicit at the beginning of each field and does not display. However, subfield ‡a does display if it is preceded by another subfield.)

1.2 Bibliographic Formats


OCLC Connexion uses eight MARC formats: Books (BKS), Continuing Resources (CNR), Visual Materials (VIS), Mixed Materials (MIX), Maps (MAP), Scores (SCO), Sound Recordings (REC), and Computer Files (COM).

Note: There are five MARC 21 data communication formats (Bibliographic, Authority, Classification, Holdings, Community Information). Under the MARC 21 Format for Bibliographic Data, there were historically eight bibliographic 'formats' for the different types of materials and modes of issuance that libraries traditionally collected (books, serials, visual materials, mixed materials, maps, scores, sound recordings, computer files). As a result of Format Integration in the 1990s, these eight 'formats' became the single integrated MARC 21 Bibliographic format, but in many contexts, they remain convenient shorthand. In this book (and in any other context of creating and editing records for materials), 'format' usually refers to these eight kinds of materials and modes of issuance. In OCLC Connexion, they correspond to the workforms used to create new bibliographic records; they also serve as search qualifiers.

Choosing a format

Together the Type (Type of Record) code and the BLvl (Bibliographic Level) code characterize the kind of library material represented by the record. You must determine the appropriate Type and BLvl for the material you are cataloging.

More information

To choose a format for electronic resources, see Cataloging Electronic Resources: OCLC-MARC Coding Guidelines (http://www.oclc.org/support/documentation/worldcat/cataloging/electronicresources/).

Format Type Code BLvl Code
Books a Language material a, c, d, m
  t Manuscript language material a, c, d, m
Textual Serials a Language material b, i, s,
Visual Materials g Projected medium a, b, c, d, i, m, s
  k Two-dimensional nonprojected graphic a, b, c, d, i, m, s
  r Three-dimensional artifact or naturally occurring object a, b, c, d, i, m, s
  o Kits a, b, c, d, i, m, s
Mixed Materials p Mixed material c, d
Maps e Cartographic material a, b, c, d, i, m, s
  f Manuscript map a, c, d, m
Scores c Printed music a, b, c, d, i, m, s
  d Manuscript music a, c, d, m
Sound Recordings i Nonmusical sound recording a, b, c, d, i, m, s
  j Musical sound recording a, b, c, d, i, m, s
Computer Files m Computer file a, b, c, d, i, m, s

BLvl codes

The following is a list of codes for BLvl. See the fixed-field elements and BLvl for more information.

a Component, monograph
b Component, serial
c Collection
d Subunit
i Integrating resource
m Monograph
s Serial

1.3 WorldCat Bibliographic Records

Master record

A bibliographic record in WorldCat is the master record. When you retrieve records, the system displays a temporary working copy of the master record. You can modify the copy for local use, but the master record does not retain these modifications. You can also upgrade the copy. In this case, the master record does retain these modifications. In either case, the system maintains an archival record of your modifications.

If a master record does not exist for the item, you may create one or derive one from an existing record.

Existing records

If a record exists for the item you want to catalog, you may modify the record for local use and add your OCLC symbol to the locations information.

Records are dynamic

WorldCat records often change because:

  • Catalogers with full-level authorizations can change most master records
  • In batchload processing:
    • Data may be merged into existing records
    • WorldCat records may occasionally be overlaid by other records, such as full-level LC records, PCC records, and some other records. In these cases, the 040 field will contain codes in subfields ‡a and ‡c for the library whose record overlaid the existing WorldCat record. If any fields transfer from the existing record, the code in its subfield ‡c transfers to field 040 subfield ‡d in the overlaid record.

Derive new records

If you retrieve a record that has information in common with the item you want to catalog, you may use that record as the basis for the new record. For example, use the record from a previous edition as the basis for a new record for a new edition or use the record from the Books format as the basis for a new record for the books on tape record.

When you derive the new record, the system transfers selected fields from the existing record to the new one.


If you do not find an existing or a similar record, you may use a workform to input a record. Workforms are templates that contain commonly used fixed-field elements, variable fields and subfields. Each of the eight formats has a specific workform.

More information

For instructions on how to modify existing MARC records, replace master records, create new records and use workforms, see the Connexion documentation (http://www.oclc.org/support/documentation/connexion/).

1.4 Information in Bibliographic Records


When entering bibliographic information in MARC records, apply the most current edition of the Anglo-American Cataloguing Rules (AACR2), and its amendments. Dublin Core users follow different practices. Use the following documents and systems to determine appropriate practice in MARC records:

LC published

  • Archival Moving Image Materials: A Cataloging Manual, 2nd. ed. (Library of Congress, 2000).
  • Codes for the Representations of Names of Languages. (Library of Congress, 2008): http://www.loc.gov/standards/iso639-2/php/code_list.php
  • CONSER Cataloging Manual (Library of Congress, 2002)
  • CONSER Editing Guide (Library of Congress, 2002)
  • Describing Archives: A Content Standard (Society of American Archivists, 2004)
  • Descriptive Cataloging of Rare Books, 2nd ed. (Library of Congress, 1991)
  • Digital Library Federation Registry of Digital Masters Record Creation Guidelines, 2nd ed. (Digital Library Federation, 2007): http://www.diglib.org/collections/reg/DigRegGuide200705.htm
  • Geographic Cutters, 2nd ed. (Library of Congress, 2001)
  • Graphic Materials: Rules for Describing Original Items and Historical Collections (Elisabeth Betz Parker, Library of Congress, 1982). Out of print, but updated to 1997 on the web: http://www.loc.gov/rr/print/gm/graphmat.html.
  • Library of Congress Rule Interpretations, 2nd ed. (Library of Congress, 2002)
  • Map Cataloging Manual. (Library of Congress, 1991)
  • MARC Code List for Countries. (Library of Congress, 2003): http://www.loc.gov/marc/countries/
  • MARC Code List for Geographic Areas. (Library of Congress, 2006): http://www.loc.gov/marc/geoareas/
  • MARC Code List for Languages. (Library of Congress, 2007): http://www.loc.gov/marc/languages/
  • MARC Code List for Organizations. (Library of Congress): http://www.loc.gov/marc/organizations/
  • Source Codes for Vocabularies, Rules, and Schemes. (Library of Congress): http://www.loc.gov/standards/sourcelist/
  • Standard Citation Forms for Published Bibliographies and Catalogs Used in Rare Book Cataloging, 2nd ed. (Peter M. VanWingen, Library of Congress, 1995)
  • Subject Headings Manual, 2008 ed. (Library of Congress, 2008)

ALA published

  • American Library Association, Anglo-American Cataloguing Rules, 2nd ed., rev. 2002, 2004 update , (AACR2)
  • Cartographic Materials: A Manual of Interpretation for AACR2, 2002 revision, 2nd ed., 2005 Update (American Library Association, 2006)

Other publishers

  • Describing Archives: A Content Standard (Society of American Archivists, 2007)
  • Music Cataloging Bulletin (Music Library Association, 1970–)
  • Symbols and Interlibrary Loan Policies in Canada (Latest edition): http://www.nlc-bnc.ca/6/16/s16-202-e.html


  • OCLC Authority File

1.5 Offline Cataloging Products


After cataloging an item, you can produce customized products such as catalog cards, accession lists and machine-readable records that conform to your local cataloging practices. OCLC generates these products from archive records of your institution's cataloging transactions.

You create an archive record by taking "final action" on a bibliographic record. For more information about final actions, see the Connexion documentation that covers taking actions.

Catalog cards

Catalog cards conform to the requirements specified by your institution. A catalog card profile describes your collections, the number and types of your catalogs, filing arrangements within each catalog and information on each card.

Accessions lists

Accessions lists represent titles processed during a given period. Lists represent current transactions. You can choose from several different sort sequences and distribution frequencies. You can mount them on your web site, distribute them electronically or reproduce them for distribution to patrons.

OCLC-MARC record services

OCLC provides electronic file transfer services. You may also export records using the Export command.

The MARC Subscription Service provides daily file transfers of your institution's cataloging transactions via the Internet.

You can use transferred files or exported records to maintain local computer-based products and services (e.g., automated circulation systems, online public access catalogs).