Skip to main content
OCLC Support

OCLC glossary

Find a comprehensive listing of OCLC terms accompanied by definitions.

A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  R  S  T  U  V  W Z



Anglo-American Cataloging Rules, 2nd edition. An international standard for the cataloging of all types of materials collected by general libraries. AACR2 has now been superseded by RDA: Resource Description and Access.

Abbreviated records

Brief records (Encoding Level 3) that do not meet the requirements of minimal-level cataloging specifications.

Abridged edition

A shortened version of the Dewey Decimal Classification (DDC) system that is a logical truncation of the notational and structural hierarchy of the corresponding full edition on which it is based. The abridged edition is intended for general collections of 20,000 titles or less. See also Broad classification; Full edition.


A brief summary that classifies, evaluates, or describes the important points in the content of a journal article or library resource.

Academic library

A library that is an integral part of a college, university, or other institution of postsecondary education, administered to meet the information and research needs of its students, faculty, and staff.

Access keys

In the Connexion client interface, underlined letters on menus, submenus, and commands, sometimes referred to as hot keys. Access keys, preceded by <Alt>, are keystrokes for executing commands (e.g., <Alt><V><U> opens the User Information window in the client). Access keys are available for all client commands.

Access method

Method used to log on to a service, download records or reports, or locate additional information. For example, a URL (Uniform Resource Locator) is used to find information on the Internet.

Access point

A name, term, code, etc., representing a specific entity that is indexed.

Access to records

Names, titles, keywords, subjects, codes, dates, and other data in bibliographic and authority records are indexed in a searchable database file such as WorldCat to make the records identifiable and retrievable.

Accession number

An identification or inventory number assigned to an item in a library's collection.

Action status

In Connexion client, an indicator in a bibliographic record that designates what actions have been taken and the outcome of each action. If taken, the following actions appear in the status bar of a displayed record: Delete Holdings, Export, Label, Produce, Replace, Update Holdings, and Validate. For each action taken, a one-character code indicates that the action completed successfully (C), failed (F), or is ready for batch processing (R).


To load an original bibliographic record into the database after data sync routines cannot find a match for it. The bibliographic record may not necessarily start out as an original record at the institution's end.

Added entry

A secondary access point for the resource. Added entry is a pre-RDA term.


Words, numbers, or symbols that designate a physical or virtual location. Examples: street numbers and names, countries, Email addresses, URLs.


American Library Association. The oldest and largest library association in the world. See About ALA for more information.

ALA character set

ALA-defined characters used in MARC records, including standard alphabetic characters, diacritics, special characters, 14 superscript characters, 14 subscript characters, and 3 Greek characters. Also known as the MARC-8 character set, these were the only characters valid in MARC records prior to the implementation of Unicode.

Allowable duplicate records

Records for the same resource, but using different cataloging languages or rules. See also Parallel records.

Anglo-American Cataloging Rules, Second edition

See AACR2.


American National Standards Institute. A nonprofit non-governmental organization composed of representatives from business and professional organizations that acts as the repository for various voluntary standards. See About ANSI for more information.

ANSI/NISO Standards for Holdings Data

Specifies display requirements for holdings statements for bibliographic resources to promote consistency in the communication and exchange of holdings information.

The standard applies to holdings statements for bibliographic resources in any physical or electronic medium. It may be applied to electronic resources available to an institution, either under its control, or available under other arrangements. It applies to both manual and automated means of recording holdings.

Any qualifier

Qualifier used to override default qualifiers. Any is also the default qualifier. If you do not qualify a search, the qualifier is any.


Computer program that provides an interface to allow computer users to accomplish certain tasks. Examples include word processors such as Microsoft Word and OCLC Connexion client for cataloging library materials.

Approval plan

A predetermined set of criteria established by an institution and a materials vendor that defines types of material to be automatically sent to the institution by the vendor. The institution accepts the items for purchase or rejects the items and sends them back.

Archive record

Prior to 2016, the bibliographic record OCLC created and stored contained local changes made by an institution to the WorldCat record. Archive records provided a complete history of an institution’s OCLC cataloging activity. OCLC used archive records to create offline products—catalog cards, magnetic tapes of records, and electronic files of records. After 2016, institutions could maintain local data in OCLC local bibliographic data (LBD) records.


An online service that provides access to detailed archival collection descriptions. It includes nearly a million descriptions of archival collections held by thousands of libraries, museums, historical societies, and archives worldwide.


The noncurrent records of an organization, regardless of format, which are maintained and preserved because of their permanent legal, fiscal, regulatory, evidential, informational, or historical value to the institution. Materials that are archived are permanently retained.


Authority Record Number (OCLC-assigned control number for authority records in the LC names and subjects authority file).

Article issue number

A number or code that identifies an article by the issue of the journal in which it appears.

Article type

Words or abbreviations that describe the format or medium used to present an article. For example, a review (rev) is an article type. An editorial is another article type.

Article volume number

A number or code that identifies an article by the volume of the journal in which it appears.


American Standard Code for Information Interchange. A standard computer character code set, consisting of alphanumeric characters, punctuation, and a few control characters (such as a carriage return). Each ASCII character consists of 7 information bits and 1 parity bit for error checking.

Assigned search key

A string of characters assigned to an item by an agency which can be used to retrieve the record for that item.

Authority control

Verifies a heading in a bibliographic record against the Library of Congress Authority File and, if a matching authority record exists, links the heading to the corresponding authority record. If the authority record is updated, the controlled (linked) heading in bibliographic records is updated automatically.

Authority file

See OCLC Authority file.

Authority history record

Copies of all distributed Library of Congress authority file records, superseded versions of distributed records, and deleted records. Retrieve these records in Connexion client using Authorities>Show>LC Distributed Version or LC Suspended Versions or using Authorities>Search>LC Names and Subject History.

Authority record

A collection of information about a name (personal, corporate, family, or meeting), preferred title, or subject term (topical, geographic, genre, etc.). An authority record can contain the authorized access point, see from references, see also from references, and notes.

Authorization level

Defines a range of tasks that can be performed when logged on to a service. Also called authorization mode.

Authorization number

Number assigned by OCLC to authorize use of OCLC services. Usually used in conjunction with a password. See also Password; Default holding library code.

Authorized Access Point

An access point, representing an entity, formulated according to a specified standard.


Indicates the institutions from which a library resource can be obtained.

A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  R  S  T  U  V  W Z


Batch processing

See Batchloading.

Batch processing in Connexion client

In Connexion client, the process of sending and completing a group of searches for bibliographic and/or authority records and/or a group o final actions in WorldCat all at once. Using client local files (files stored on the Connexion client cataloger's workstation), the cataloger enters search strings and/or marks saved records for actions and then initiates batch processing. The client automatically logs on to the system, runs the WorldCat searches and/or processes record actions, and produces reports, accessible in the client, for the results.

Batch processing limits in Connexion client

None. Batch processing is limited only by the size of your hard drive. Note: Local files used for batch processing are limited to storing no more than 9,999 records. However, Connexion users can run as many local files as you want in a single batch.


A service by which records were matched and/or added to WorldCat in batches. The batchloading service was replaced by OCLC Data Sync in 2017.


Monographic Bibliographic Record Cooperative Program (BIBCO) is one of the programs of the Program for Cooperative Cataloging (PCC).  BIBCO participants contribute monographic bibliographic records in all formats to WorldCat and other international databases.  Records meet or exceed the BIBCO Standard Record (BSR) requirements and have the "pcc" code in the 042 field. See also PCC.

Bibliographic database

A computer file consisting of electronic entries called records, each containing a uniform description of a specific document or bibliographic item, usually retrievable by author, title, subject heading (descriptor), or keyword(s). Some bibliographic databases are general in scope and coverage; others provide access to the literature of a specific discipline or group of disciplines. An increasing number provide the full-text of at least a portion of the sources indexed. Most bibliographic databases are proprietary, available by licensing agreement from vendors, or directly from the abstracting and indexing services that create them.

Bibliographic formats

The standardized sequence, and manner of presentation of the data elements constituting the full description of a resource in a specific cataloging or indexing system. The machine-readable MARC record format has become the standard for library catalogs in many countries of the world. OCLC refers to eight bibliographic formats. In Connexion, the bibliographic formats correspond to the workforms used to create new bibliographic records. In WorldShare Record Manager, these workforms are known as material type templates. See also Books formatComputer Files formatContinuing Resources formatMaps formatMixed Materials formatScores formatSound Recordings format; and Visual Materials format.

Bibliographic Formats and Standards

Guide to machine-readable cataloging records in WorldCat. This guide provides tagging conventions, input standards, and guidelines for entering information into WorldCat. See Bibliographic Formats and Standards.

Bibliographic record

A description of the physical or virtual format and intellectual content of a single resource (a book, video, map, etc.) encoded in a standardized format such as MARC.

Bibliographic Record Processing Summary

A summary of statistics after processing a batch of records using the OCLC data sync service. See OCLC WorldShare Collection Manager data sync collections.

Bibliographic save file

In Connexion, a working storage area online or a local file (on your workstation or network) to use for completing new bibliographic records or modifying existing WorldCat records. Limit of 9,999 records for either online file or local file(s).


See Books format.

Blank workform

A template for creating an interlibrary loan request or (in Connexion) a cataloging template for creating new records.

Book number

The part of a call number that distinguishes a specific item from other items within the same class number, also called a Cutter number. A book number is composed of letters from the author's name or letters from the title main entry and numbers. There are several systems for creating book numbers.

Books format

OCLC-MARC Bibliographic format used for cataloging monographic non-manuscript language or textual material (including all published print language material, original microform publications of language material, microform reproductions of published language material, and published textual electronic resources). The three-character format designator and index qualifier for books is "BKS".

Books with feet

Refers to library books that are commonly lost, stolen, vandalized, or misshelved. They are typically popular titles and cover a wide range of subjects and contemporary issues.

Boolean logic (searches)

A system of logical thought developed by English mathematician George Boole (1815-64). A Boolean search combines key concepts or search terms with the logic operators AND, OR, and NOT to specify the exact information required in a database search.

Boolean operators

AND, OR, and NOT. Used to combine search terms. AND finds only records that contain both terms. OR finds records that contain either term. NOT finds records that contain the first term but not the second term. Combining search terms produces more precise and manageable search results.

Borrowing record

In WorldCat Resource Sharing, the record for which a library participates as the Borrower.

Bracketed information

Descriptive information that has been provided by the cataloger added to a bibliographic record inside square brackets ([ ]).

Brief list

Default display of WorldCat search results when a Connexion search retrieves 2 to 5 records.

Broad classification

The classification of works in broad categories by logical abridgment, even when more specific numbers are available, e.g., the use of 641.5 Cooking instead of 641.5972 Mexican cooking for a cookbook of Mexican recipes. Broad classification is the opposite of close classification. See also Abridged edition; Close classification.


Scan an index for a match or the closest match to a term (word, phrase, or whole phrase) in records. The system matches the exact text string—character by character, from left to right—against the characters in the specified index. Produces a browse list that highlights the closest match and shows the number of records for each item in the list. Clicking an entry opens the record or a record list, if multiple records match.

A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  R  S  T  U  V  W Z


Calendar days

WorldCat Resource Sharing sequential days, including weekends and holidays. See also System days.

Call number

A set of letters, numerals, or other symbols (in combination or alone) used by a library to identify a specific copy of a resource. A call number may consist of the class number; book number; and other data such as date, volume number, copy number, and location symbol. A call number indicates the relative position of the copy on the shelf, facilitating browsing.


Catalog of Art Museum Images Online. Developed by RLG, a database of artwork images.


See Delete.


Describes data you can enter in uppercase, lowercase, and mixed case. You do not have to match the case exactly.


Describes data you must enter exactly as it appears, matching upper- and lower-case.

Cataloging Agent mode

An authorization mode that allows the Cataloging Agent of an institution or a group to process cataloging records on a client's behalf. Agents may also process unresolved records from the group's data sync activity. See also Processing center.

Cataloging In Publication

A Library of Congress program that provides bibliographic data for new books in advance of publication. Records are created from information supplied by publishers. Records are available for distribution and loading into bibliographic databases.

Cataloging Label Program

An OCLC service that lets users of OCLC cataloging products easily print labels for library materials. The free Windows software manages the creation, display, editing, and printing of pocket and spine cataloging labels.

Cataloging profile

See OCLC cataloging profile.

Cataloging source

The authority or bibliographic fixed-field element (008/39) has coded data indicating the source of the data. Abbreviations for this element differ depending upon the interface:

  • Source (Connexion authority)
  • Srce (Connexion bibliographic)
  • Cataloging Source Code (Record Manager authority and bibliographic)

In addition, the authority and bibliographic Cataloging Source field 040 indicates the agencies that created and/or edited the record in WorldCat.

Cataloging source qualifier

Qualifier index (label cs=) that can be used to limit WorldCat searches to records contributed by a specific library identified by its OCLC symbol (for example, cs=ocl).

 Note: To limit searches to records contributed by the Library of Congress or by specific LC cooperative programs, use cooperative programs index (label dl:) with value y (dl:y).


See OCLC CatExpress.

Central concept

Main idea behind the content of the library resource.


Consortium of European Research Libraries

Character masking

Entering a question mark (?) or number sign (#) in a search in place of other characters to retrieve multiple words. Example: computer? retrieves records that contain computer, computerization, or computerized.


Types of dates used by publishers to identify the individual bibliographic unit of a serial, for example, date of coverage, date of publication, or date of printing.


An abbreviation referring to the Chinese, Japanese, and Korean languages and characters sets.


See Cataloging In Publication.


The character (^) entered in certain segments of numeric and derived searches in WorldCat to make searches more precise. Also known as caret.


A list that contains terms that identify whole or parts of library resources so that they may be found.


A logical system for the arrangement of knowledge, including notations for identifying where in a classification a given item belongs.

Classification number

The part of a call number, usually a combination of letters and numbers, used to classify library resources by subject area using a particular classification system.

Classification system

A list of classes arranged according to a set of pre-established principles for the purpose of organizing items in a collection, or entries in an index, bibliography, or catalog, into groups based on their similarities and differences, to facilitate access and retrieval (i.e., classification by subject). Classification systems can be enumerative or hierarchical, broad or close. Examples of classification systems include Dewey Decimal Classification and Library of Congress Classification.


(1) To arrange a collection of items according to a classification system. (2) To assign a classification number to an individual work.

Classify Web service

A FRBR-based, prototype service created by OCLC Research for automatically retrieving classification numbers for books, DVDs, CDs, and other types of materials. Available in the client via the Edit > Classify command, the service retrieves and inserts a suggested call number for a displayed bibliographic record.

Click-through dialogs

Wizards in CONTENTdm that help simplify the process of entering descriptive and administrative metadata in both simple and compound records.

Close classification

The classification of works to the fullest extent permitted by the notation. Close classification is the opposite of broad classification. See also Broad classification; Full edition.


See Continuing Resources format.


A unique 6-character code assigned by the Chemical Abstracts Service (CAS) to identify serial and non-serial publications in all subject areas.


(1) Library resources grouped by a specific topic or other organization criteria; (2) the entire holdings of a library; (3) all library resources on a particular subject.

Collection Sets

Officially called WorldCat Collection Sets. An OCLC service that provides MARC records for collections of already-cataloged microform, non-microform, and electronic content.


See Computer File format.

Command line search

A type of Connexion WorldCat search that allows you to type (1) any complete keyword, numeric, or derived search in a single string, including index labels, qualifiers, and Boolean operators, or (2) a browse string, including the Scan (sca) command and index label in the format sca xx:.

 Note: The equivalent search capability in FirstSearch/Resource Sharing is called an "expert search."

Communications format

The communications format presents a MARC record in a form that looks like one long run-on sentence, in which the fields are not preceded by tags. Immediately following the leader is a block of data called a directory. This directory tells what tags are in the record and where they are placed by a count of the characters to the position where each field begins. The directory is constructed, by computer, from the bibliographic record, based on the cataloging information, and, if any of the cataloging information is altered, can be reconstructed in the same way. See also MARC (Machine-Readable Cataloging).


An indication of how much of a published run of a serial is held. Completeness is indicated in ranges, for example, Complete (95%-100% held), Incomplete (50%-94% held), (Scattered (less than 50% held).

Computer Files format

OCLC-MARC Bibliographic format used for cataloging computer software (including programs, games, fonts), numeric data, computer-oriented multimedia, online systems or services; the three-character format designator for computer files is “COM”.

Conference name

See Meeting name.

Conference name phrase

The exact name or title of a conference that is the focus of a search. A conference name could be included in a title, abstract, notes, or text of a library resource.


See OCLC Connexion.

Connexion browser interface

See OCLC Connexion browser.

Connexion client interface

See OCLC Connexion client.


Cooperative Serials Program (CONSER, which originally stood for CONversion of SERials) is the oldest program of the Program for Cooperative Cataloging (PCC). CONSER participants contribute records for serials and integrating resources to WorldCat, where the CONSER database resides. Records meet or exceed the CONSER Standard Record (CSR) requirements and have the code "pcc" in the 042 field. See also PCC.

Constant data record

A partial record that contains standardized content for reuse in creating or editing a record without having to retype each time the content is reused. Constant data records are created by and shared among librarians at a given institution for cataloging and resource sharing activities.

Content designation

The tags, indicators, codes, and other conventions established explicitly by MARC 21 to identify and further characterize the data elements within a record and to support the manipulation of that data. MARC 21 attempts to preserve content designator consistency across formats where appropriate. See also Record structure.


OCLC's digital collection software suite. It allows you to digitize, store, search, and mount your digital objects on the Web.

Context-sensitive Help

Topic you open using <F1> or a Help button in a dialog window to describe each feature of the dialog.

Continuing Resources format

OCLC-MARC format used for cataloging items issued over time with no predetermined conclusion. The Continuing Resources format includes serials and ongoing integrating resources. In WorldCat searches, use the Continuing Resources index (label: cnr) as a qualifier to limit results to records for this type of material.

Contract cataloging

OCLC service that catalogs libraries' collections as their cataloging agent. Formerly called TechPro or Custom Cataloging.

Control field

A 00x field. Control fields are structurally different from variable data fields containing neither indicator positions nor subfield codes. They may contain either a single data element or a series of fixed-length data elements. Although field 007 does not have indicators or subfield codes, it displays in subfielded form in Connexion interfaces.

Copy cataloging

Using and modifying an existing bibliographic record for local use. OCLC creates and stores an archive record of the modifications at OCLC.

Copyright compliance

Guidelines that relate directly to WorldCat Resource Sharing: Guidelines for the Proviso of Subsection 108 (g) (2). Borrower is responsible for ensuring that the request conforms with U.S. Copyright law; request must include code ccg (conforms to Copyright Guidelines) or ccl (conforms to Copyright Law).

Corporate name

The name of an agency, association, business, firm, government, institution, nonprofit enterprise, performing group, etc. used as an authorized access point in a bibliographic record.

Corporate/Conference name derived search

See Derived search.


See OCLC Customer Services Division.

Custom holdings

Customized groups of preferred lenders; you define the groups for sets of similar requests.

Custom Holdings Group record

A record that contains OCLC symbols of preferred lenders within a particular category (for example, Books or State).

Custom holdings locations record

A display associated with a WorldCat record that lists institutions from which you prefer to borrow.

Custom Holdings Path record

A record that contains one or more custom holdings group records sorted in order of borrowing preference.

Cutter number

A notation derived from the main entry and added to the class number to order materials within classes. Cutter numbers can be derived from the Cutter Three-Figure Author Table, the Cutter-Sanborn Three-Figure Author Table, or the OCLC Four-Figure Cutter Tables. The notation often, but not always, combines alphabetic characters representing an author’s surname with numerals. The class and Cutter notations together form a call number intended to be unique within a particular collection of resources.

A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  R  S  T  U  V  W Z



A grouping of electronic data for a particular purpose or for the use of a particular set of users. Each entry in the database is a record. The database provides an interface that has tools to enable manipulation of the data for sorting, grouping, searching, etc.

Database enrichment

A capability that allows modifications of WorldCat records

Data Sync Collection Profile

The specifications for an institution's OCLC data sync project. The data sync collection profile details the general properties about the project, information about the bibliographic records, outlines local bibliographic data for retention, specifies the MARC record output if necessary, and allows for contact information and correspondence. See OCLC WorldShare Collection Manager data sync collections.

Data sync with output with OCLC Number

An option for an institution to elect to receive a copy of the matching OCLC MARC bibliographic record when it sets its holding symbol in WorldCat through the OCLC data sync service. Alternatively, the institution may choose to receive their own record(s) back.

Date of entry

Date a new or updated bibliographic citation is included in a database.

DBID source

Database Identifier source. An identifying number or term that refers to a source journal or primary database from which a cited library resource came.


See Direct Consortial Borrowing (DCB).


See Dewey Decimal Classification.


See Duplicate detection and resolution.

Decomposed diacritics

Two or more characters where a letter is entered first followed by one or more diacritical marks that display as one character.

For example, the base letter e (U+0065) followed by the combining acute accent (U+0301) which displays as é.

See also DiacriticPrecomposed diacritics.


Selections made by the computer or a software program in the absence of specific instructions by the user. For example, the Connexion client pre-sets some options and supplies one of each type of local file (files are empty) when you first install the program.

Default constant data

A constant data record set as the default content to apply to record(s) you create or edit.

Default holding library code

The holding library code is a four-character code associated with a specific OCLC symbol.  It appears automatically in data fields when a user displays a bibliographic record (field 049 subfield $a) or local holdings record (field 852 subfield $b).

Default holdings display

The system responds to a display holdings command with a list of all, regional, or state holdings on a record, depending upon the number of holdings the record has.

Default qualifiers

In the Connexion client, a specified qualifier that is automatically applied to batch search keys. Default qualifiers cannot be set in other types of searching in the Connexion client.

Default settings

Settings and options that are preset in Connexion client when you install it. For example, the client provides default keystroke shortcuts for entering diacritics and special characters. You can change default settings to customize the program.

Default values in workforms

Values automatically supplied in workforms (templates for creating MARC records), depending on the MARC format selected for the new record.

Default WorldCat search results displays

System-determined displays of WorldCat search results as group, truncated, or brief lists or as a full record. The default display type is based on the number of records the search retrieves.


A decision process that can happen multiple times within the life-cycle of a request using lending rules set up in the Policies Directory. Deflection is performed on the lender string.


Action to remove an institution's OCLC symbol from a record in the database. This can be done one of two ways: Create a Delete WorldCat Holdings collection within data sync collections or create a Bibliographic collection with Record Status element set to "Use". Data sync cancels the holding on the matching record when a match is found and the Record Status element (Leader byte 5) contains the character "d". This is equivalent to the Delete Holdings command in the Connexion client and browser.


See Subfield delimiter.

Derive new record

For cataloging in Connexion, using a pre-existing record to create a new record to add to the system.

Derived search

A type of WorldCat search that uses a specific number of initial characters from the words in a name and/or title. A shortcut way to enter a search. The "derived" segments of the words are separated by commas. The number and pattern of letters and commas tells the system which index to search. The four types of derived searches (with the pattern that defines it in parentheses) are: Title (3,2,2,1); Personal name (4,3,1); Corporate/Conference name (4,3,1); Name/Title (4,4).


(1) A term that describes the theme or topic of the content of a library resource. (2) A standardized term assigned to database records to facilitate retrieval of records in a search.

Detailed level information

Holdings statement at the most detailed level of enumeration and chronology. See also Level 4.

Dewey class number

See Dewey Decimal class number.

Dewey Decimal class

See Dewey Decimal class number.

Dewey Decimal class number

A classification number that conforms to the conventions used in the Dewey Decimal Classification system. The classes used to identify library resources are: 000, General Works; 100, Philosophy & Psychology; 200, Religion; 300, Social Sciences; 400, Language; 500, Natural Sciences & Math; 600, Applied Sciences (Technology); 700, Fine Arts; 800, Literature; 900, Geography & History.

Dewey Decimal Classification

A general knowledge organization tool conceived by Melvil Dewey in 1873 and first published in 1876. At the broadest level, the Dewey Decimal Classification (DDC) is divided into ten main classes organized by disciplines or fields of study. Together these classes cover the entire world of knowledge. See also Dewey Decimal class number.

Dewey Decimal subject heading

Used in the Dewey Decimal Classification system to identify library resources by disciplines or areas of knowledge.

Dewey Services Only session

A Connexion session that provides access to WebDewey and/or Abridged WebDewey. A Dewey Services Only session: does not access and user support fees; does not count against simultaneous logon limits for libraries subscribing to flat fee Internet or dedicated TCP/IP access; and includes a default inactivity timeout of 120 minutes (default timeout for other Connexion sessions is 40 minutes). Authorized users can start a Dewey Services Only session from the Connexion logon screen or from within an active Connexion cataloging session.

Dewey subject heading phrase

The specific terms used to identify Dewey subject headings or subsets of those headings. Browse the Dewey subject heading phrase index for valid phrases.


A mark that modifies the phonetic value of some other character or characters. It is always used in conjunction with another character.

In records coded as MARC-8, each diacritic occupies its own position, directly following the modified character, although the diacritic displays correctly in relation to its character.

In records coded as UTF-8, both precomposed and decomposed diacritics may be used.

See also Precomposed diacritics; Decomposed diacritics.


In Connexion, a window that opens when a command you issue requires input before a task can be completed or when you click a button to select options and settings. Most usually, called a "window" in Connexion client and a "screen" in Connexion browser. Dialogs provide text boxes, lists, buttons and other elements for entering data, making selections, and clicking more commands to tell Connexion what to do.

Digital Archive

OCLC service that provides long-term storage of digital documents in multiple formats. Based on the OAIS (Reference Model for an Open Archival Information System) ISO standards and utilizes the METS (Metadata Encoding and Transmission Standard).

Digital Collection Gateway

The WorldCat Digital Collection Gateway provides OCLC subscribers with a self-service tool for uploading the metadata of their unique digital content to WorldCat. Once the metadata is in WorldCat, library collections are more visible and discoverable by end users who search, WorldCat Local and WorldCat Local "quick start", as well as Google, Yahoo!, and other popular Web sites.

Direct Consortial Borrowing (DCB)

An arrangement allowing users of one agency to request and borrow items from another agency within a consortium. As a DCB agency, OCLC uses NCIP (NISO Circulation Interchange Protocol) to facilitate the transfer of user identification and item information between different circulation systems, allowing OCLC to manage traffic for non-local patrons and/or provide local control for items belonging to another agency.

Direct delivery

An OCLC Resource Sharing option that allows a lending library to send an item directly to the requestor/patron rather than to the borrowing library.

Direct Request

An OCLC ISO-10161-based service that provides a means to send patron-generated requests automatically to WorldCat Resource Sharing. See also ISO 10160/10161. See Automated Request Manager for more information.


Within each MARC record, a series of fixed-length entries, with one entry for each variable field (control or data) present in a record. Each Directory entry contains three portions: the field tag, the field length, and the starting character position. The Directory immediately follows the Leader at the beginning of the record.

Display holdings

A command to view the list of institution symbols that hold an item. In WorldCat Resource Sharing, used to select potential lenders.

Document supplier

Major national resource centers and other document suppliers such as the British Library Document Supply Center.


All or part of an Internet name, address or element that identifies a computer and the organization that transmits or receives electronic data.

Dublin Core

An international standard that supports creation of simple, informative descriptions of electronic resources that facilitate management and discovery. The Dublin Core standard defines 15 elements for a resource description. Users can define additional elements or qualifiers for the standard elements to adapt Dublin Core to meet their needs. The standard elements provide a shared semantic framework that allows communities operating under different rules or standards to exchange metadata.

Dublin Core has as its goals the following characteristics: simple creation and maintenance, commonly understood semantics, international scope, and extensibility.

For more information, visit the official DCMI site.

Duplicate detection and resolution

Software that identifies and merges duplicate records in books and serials format. The software uses complex algorithms and can match some records that failed to match in regular data sync processing. For example, regular data sync does not match the publisher strings Charles Scribner and Chas. Scribner. DDR software may find that all other criteria match, recognize the identical Scribner strings in the publisher, and determine that the records match. OCLC uses this software at its discretion, based on a given file's probable matching rate and probable duplication rate.

Duplicate record

See Allowable duplicate records.

A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  R  S  T  U  V  W Z



East Asian Character Code. A set of unique 3-byte hexadecimal codes used to represent and store in machine-readable form all Chinese, Japanese, and Korean characters used in the USMARC format.

Electronic Collections Online (ECO)

An OCLC service that offers Web access to a collection of electronic journals, letting libraries subscribe to individual journals and provide access to them for their end users through a single Web interface.

Electronic Data Exchange (EDX)

A decommissioned OCLC method of data exchange via FTP. It was a method for libraries to send and receive files.

Electronic document supplier

Document supplier that accepts WorldCat Resource Sharing requests and delivers full-text documents through messages to your library's Email system.

Electronic resource

See Computer File format.


See Encoding Level.


Electronic mail. The exchange of electronic messages created by a user on a computer and transmitted (via an organization's network or the Internet) to another user's computer.

Embedded holdings data

Holdings information contained in an existing MARC 21 bibliographic record rather than being in a separate local holdings record.


See Enter-my-symbol-twice institution.

Enc lvl

See Encoding Level.

Encoding Level
  1. In bibliographic records, the Encoding Level represents the completeness of the record. It is identified in MARC 21 as Leader/17 and in Connexion as ELvl in the fixed fields, or in Record Manger as Encoding Level. Requirements for each encoding level in bibliographic records have varied over time. Correspondence between data in records and descriptive cataloging instructions is not exact.
  2. In authority records, the Encoding Level represents the completeness of the record. It is identified in MARC 21 as Leader/17 and in Connexion as Enc lvl in the fixed fields, or in Record Manager as Encoding Level.
  3. In holdings records, the Encoding Level represents the level of specificity of the holdings statement. It is identified in MARC 21 as Leader/17 and in Connexion and Record Manager as Encoding Level. Codes in holdings records reflect requirements of Holdings Statements for Bibliographic Items (ANSI/NISO Z39.71) and Holdings Statements-Summary Level (ISO 10324).

Enhance was a former OCLC program, established in 1983, that began the process of decentralizing responsibility for bibliographic quality control in WorldCat. Regular Enhance enabled specially authorized members of the cooperative to edit, upgrade, and replace full-level member input records in non-serial formats. National Level Enhance, instituted in 1994, enabled authorized Library of Congress catalogers and other participants in the Program for Cooperative Cataloging (PCC) to edit, upgrade, and replace full-level non-serial PCC records. Beginning in 2009, Regular Enhance was gradually superseded by the expanded editing and replacement capabilities of the OCLC Expert Community. National Level Enhance continues as the means by which PCC participants do BIBCO work in WorldCat. See also Expert Community.

Enter-my-symbol-twice institution

A potential Lender participating in resource sharing that requires more than four system days to respond to an ILL request.


A class of key conceptual objects of interest to users of information describing bibliographic data. In RDA entities include agent, collective agent, corporate body, expression, family, item, manifestation, nomen, person, place, timespan, and work.


A designation in numeric and/or alphabetic form, rather than in chronological form, presented for a serial issued in a sequence of numbering to show the relationship of the individual unit of the serial to the series as a whole. For example, Volume 235 and Volume XII are indicators of enumeration.

Error rate

The percentage of records within a file that contain validation errors.


Formerly, a group of RLG databases. Most of the Eureka databases have become part of OCLC FirstSearch.


The evaluation of bibliographic records sent for data sync processing involves analysis of the data. Data Sync staff identify problems with the records as well as problems with the file structure. All of this analysis is done to obtain the highest and most accurate hit rate for a project.

An automated portion of the data sync process that identifies and corrects some critical errors to allow for better processing and matching. If left uncorrected, these errors could prevent data sync from processing the records.

Executable file

File that runs a software program. The client executable file is Connex.exe.

Expert Community

Beginning in 2009, the Expert Community is an expansion of the WorldCat record editing capabilities of the Enhance program to all full level cataloging users. OCLC's Expert Community provides Connexion users who have a full level authorization or higher more flexibility in making changes to WorldCat records. Maintenance of WorldCat is shared more equally between OCLC staff and member libraries. See also Enhance.


(1) A command or action that causes a record to be converted to MARC 21, MARCXML, Dublin Core, or MODS format and output to a file on a workstation or in a local system. (2) Downloading a record from WorldCat.

Export to TCP/IP connection

Export one or more bibliographic or authority records directly to a local library system via a TCP/IP port. Establishing the export connection may require configuration of the local system and firewall.


RDA defines an expression as an intellectual or artistic realization of a work in the form of alpha-numeric, musical or choreographic notation, sound, image, object, movement, etc., or any combination of such forms.


Middleware that authenticates library users against local authentication systems and provides remote access to licensed content based on the user's authorization.

A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  R  S  T  U  V  W Z


Family name

See Surname.


In a bibliographic, authority, or holdings record, a tag in which the same kind of information is consistently entered. For example, bibliographic tag 245 is a field that consistently contains title information.

File structure

See Record structure.

File transfer protocol (FTP)

See FTP.

Filing indicator

In bibliographic records, determines how many initial characters the system omits before indexing the field.

Fill character

A black box or vertical bar that represents content that must have valid data, or where no attempt is made to code the data.

Final OCLC actions

Actions catalogers take on records to accomplish specific tasks, such as adding holdings to a record, exporting a record to a local system, adding a new WorldCat record, or replacing an existing WorldCat record. See commands on the Action menu in Connexion client or in the Action list in Connexion browser.

Actions that libraries are permitted to take on records are part of each library's cataloging profile and are identified by the system by the authorization the library uses to log on.


OCLC FirstSearch is an online reference service with a collection of databases, full-text articles, full-image articles, library holdings, and interlibrary loan. It supports research in a wide range of subject areas with well-known bibliographic and full-text databases in addition to ready-reference tools such as directories, almanacs, and encyclopedias.

FirstSearch/ILL Direct Request Link

A link between OCLC Direct Request and the OCLC FirstSearch service that allows patrons to generate requests for materials cited in FirstSearch databases.

Fixed field

The OCLC Fixed Field consists of elements of the MARC 21 Bibliographic Leader and field 008, in addition to control fields 001 and 005. The Fixed Field may be displayed as a single area with mnemonic labels for each element or as a separate variable field in Connexion client and WorldShare Record Manager. Fixed fields, and each element within a fixed field, have a fixed length. Each element is identified by its position. Other fields with fixed-length elements are 006 and 007.

Fixed-length data element

An element in a record whose length cannot be changed.

Forced add

The loading of a file of records to the database without attempting to find matching records and without validating their data. OCLC does a forced add rarely, when materials in the file are so unusual that matching records in the database are unlikely.


See Given name.


A standard for the representation and exchange of data in machine-readable form. There are five MARC 21 data communication formats: Authority, Bibliographic, Classification, Community Information, and Holdings. See also Bibliographic formats.


Functional Requirements for Bibliographic Records. An approach to consolidate different versions of the same content. See IFLA's Functional Requirements for Bibliographic Records for more details.


The interval at which a continuing resource is issued. Examples include weekly, monthly, quarterly, annually, and irregularly.

Fretwell-Downing Informatics

Based in Sheffield, United Kingdom, with operations in Europe, North America and Australia, Fretwell-Downing Informatics (FDI) is a document delivery and ILS provider. Fretwell-Downing was acquired by OCLC in 2005.


File Transfer Protocol (FTP)/Secure File Transfer Protocol (SFTP) is a TCP/IP-based protocol that is generally available for file transfers to and from a large variety of hosts. FTP/SFTP is the method used to send and retrieve files.

Full edition

The complete version of the Dewey Decimal Classification (DDC) system. See also Abridged edition; Close classification.

Full mode

The authorization level used to log on to the system for copy cataloging and original cataloging activities. With a Full level authorization, catalogers can add and replace or set or delete holdings on WorldCat records or work with bibliographic institution records.

Full stop

In cataloging, a full stop is a period ( . ), colon ( : ), semicolon ( ; ), question mark ( ? ), or exclamation point ( ! ).

Full text

The complete contents of a library resource that is text based, as opposed to an abstract or a bibliographic record.

Full text option

See Electronic document supplier.

Full-level record

A Full-level cataloging record seeks to ensure inclusion of the essential data elements necessary to meet user needs. It is a solid "floor" description of a resource that can be built upon in a shared environment. Full-level cataloging does not preclude the use of data in a bibliographic description representing more extensive cataloging treatment. Generally, full-level cataloging meets the requirements of RDA Core (RDA 1.3) or AACR2 second-level description (AACR2 1.0D2). Full-level cataloging uses ELvl codes I or blank.

Function keys

Keys and key combinations on the keyboard that transmit signals not associated with printable or displayable characters (examples: F1, F2, etc). In specific applications, such as OCLC Connexion, function keys are programmed to initiate commands.

A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  R  S  T  U  V  W Z



Group Access Capability. A group of institutions that use the OCLC system for resource sharing and interlibrary lending. A GAC has full and selective members. A selective user has access to only abbreviated bibliographic records, and only to records for its own group. Groups are composed of at least one Full member and may include Selective members who use WorldCat Resource Sharing only. GAC can also refer to the group itself.


Group Access Capability/Union List. The same as a GAC, but a selective user also has access to local holdings records for its group.

General retention policy

Denotes the period for which the serial is retained or held by the location, for example, Permanently retained, Retained for a limited period, and Not retained.

Given name

A name chosen for a person at birth that identifies and differentiates that person from others in the same family. Depending on the culture a person is born into, the given name can precede or follow a surname (i.e. family name). A given name may also be known as a forename, first name, or personal name. See also Surname.

Government document number

Government-assigned number for materials provided at the expense of and by the authority of any office of the government, for example, United States Superintendent of Documents (SuDoc) numbers.

Group Access Union List group

An OCLC Union List group in which some members are not OCLC Cataloging members and have limited access to OCLC services.

Group list

In Connexion, the default display of WorldCat search results with a search retrieves 101 to 1500 records. Groups of records are sorted by type of material and year of publication. Clicking an entry opens a brief or truncated list, depending on the number of records represented by the group list entry. 1500 is the system limit for retrieving WorldCat records.

Group Services

OCLC service that helps libraries join to purchase, usually for a discount from the price each would pay to purchase the services on their own. Includes Group Catalog, a subset of all the WorldCat records cataloged by members of the group.

Guided entry

Edit or create a field by using text boxes and lists to enter or change data.

Guided search

Text boxes and lists of indexes and qualifiers to enter or select the parts of a search, for example for WorldCat, LC authority, or save file records. For entering searches without having to remember indexes, labels, correct order for searches, etc., as you do for command line searches.

A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  R  S  T  U  V  W Z


Hand Press Book (HPB)

The HPB database includes records for European printing of the hand-press period (circa 1455-1830) from the Consortium of European Research Libraries (CERL), whose members represent national and university libraries in 16 countries. The database is available to CERL members only.

Heading on a list

On the first line of each list or bibliographic record is a heading that describes the search and indicates the number of records retrieved. Depending on the search, the description may include database name, index labels, title phrases, keywords, numeric derived search, qualifier labels and qualifiers.


Electronic user documentation that is available from the Help menu of a specific product such as Connexion, FirstSearch, etc.


The number of records or the number of times a record or word is found as a result of searching the system.

Holding library

The library or collection within an institution represented by the holding library code.

Holding library code

A unique 4-character code that identifies a holding library or collection within an institution.  For 3-character OCLC symbols, the holding library is often the OCLC symbol and another character. For example ADRR, when the OCLC symbol is ADR. See also OCLC symbol


The total stock of materials, print and nonprint, owned by a library or library system, usually listed in its catalog. Synonymous in this sense with library collection. In a narrower sense, all the copies, volumes, issues, or parts of an item owned by a library, especially a serial publication, indicated in a holdings statement in the record representing the item in the catalog. Holdings can be recorded in the MARC 21 Format for Holdings Information.

Holdings display

A list of OCLC symbols of institutions that hold the item. A holdings display accompanies each bibliographic record in WorldCat.

Holdings level

There are four levels of holdings specificity, ranging from a simple statement that the library holds the resource on up to a complex, detailed statement of exactly what parts of the resource are held. For the four levels, see OCLC Z39.71 Local Holdings Maintenance (Table 1: Levels of Specificity).

Holdings record

A record containing the location, status, and/or copies associated with a single bibliographic item of a specific publication held by a particular institution.

Holdings symbol

See OCLC holding library code.

Hot keys

See Access keys.

A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  R  S  T  U  V  W Z



A significant term, number, acronym, name, or symbol used alone or with other identifiers to refer to a library resource.


International Federation of Library Associations and Institutions IFLA is the leading international body representing the interests of library and information services and their users. As an independent, international, non-governmental, not-for-profit organization, IFLA aims to promote high standards of provision and delivery of library and information services, encourage widespread understanding of the value of good library and information services, and represent the interests of its members throughout the world. The Royal Library, the national library of the Netherlands, in The Hague, provides facilities for IFLA's headquarters.


Institution Holdings Bit (IHB) is represented in online displays by the OCLC symbol.


Interlibrary loan. When a book or other item needed by a registered borrower is checked out, unavailable for some other reason, or not owned by the library, a patron may request that it be borrowed from another library by filling out an interlibrary loan request form at a service desk or on the library's Web site. Some libraries also accept ILL requests via Email or telephone. Interlibrary loan is a form of resource sharing that depends on maintaining union catalogs. See also WorldCat Resource Sharing.

ILL cycle

Interaction between Borrower and Lender during an interlibrary loan transaction.

ILL Fee Management service (IFM)

A service that provides a means to pay and be paid for interlibrary loan requests through your OCLC invoice.

ILL Reasons for NO report

Monthly data about Borrower and Lender activity furnished electronically at no charge. This report records the ISO-specific reason a Lender was unable to lend a requested item.

ILL record

A record with an identification number created when a Borrower produces a workform, that is, sends the request to the first potential lender.


Graphics used to clarify or enhance the content of electronic or paper text.


Integrated Local System. See Local system.

Import records

Import bibliographic or authority records from a local system or from offline services into the Connexion client online or local save file to (1) add to WorldCat, (2) further process records received from an offline service such as WorldCat cataloging partner collections, or (3) process unresolved Batchload records. The Import Records command is on the File menu.


See Integrating resource.


A detailed alphabetical or numerical list for a specific kind of bibliographic data provided by the system for retrieving a record or sets of records from a database such as WorldCat.

Index label

A two- or three-character code followed by a colon or equal sign that indicates to the system the index against which to match a search term.


Either of the first two character positions in the variable data fields that contain values which interpret or supplement the data found in the field. Indicator values are usually interpreted independently and supply information about the field for indexing and other system functions.

Initial article

Words such as a, an, the, and the non-English equivalents that are the first word in a title or corporate name. See also Nonfiling indicator.

Input Method Editor (IME)

A tool to enter East Asian language characters with a keyboard. If you install CJK languages on your workstation, Windows automatically supplies the appropriate IMEs.

Input stamp

Data appended to a call number, representing the location, copy number, or other local information for an item.


A library, a library system, an organization, or a part of a library, library system, or organization.

Institution profile

A term synonymous with Cataloging Profile. See also OCLC cataloging profile.

Institution symbol

See OCLC symbol.

Institution-specific file

Records accessible only to an individual institution and OCLC that have been used or will be used by the institution.

Integrated local system (ILS)

See Local system.

Integrating resource

A continuing resource that is added to or changed by means of updates that do not remain discrete but are integrated into the whole. Includes loose-leaf manuals that are updated by means of replacement pages, continuously updated websites, continuously updated databases, etc. The three-character format designator for integrating resources is "NIT".

International Standard Book Number (ISBN)

A unique identification number assigned to a work by its publisher. OCLC has converted the existing 10-character ISBN to the new 13-character format. The thirteenth character is a check character that may be a number or the letter x. In printed form, the ISBN has three hyphens. Hyphens are omitted in online records. ISBNs are stored in field 020 in bibliographic records.

International Standard Serial Number (ISSN)

A unique identification number assigned to a serial through the ISSN Network. Each ISSN has eight characters. The eighth character is a check character that may be a number or the letter x. A hyphen follows the fourth character.


International Organization for Standardization. A name derived from the Greek word isos, meaning "equal." Founded in London in 1947 with headquarters in Geneva, ISO is a nongovernmental federation of national standardization organizations in 130 countries, dedicated to establishing international standards to facilitate commerce and cooperation in scientific, technical, and economic endeavors. The United States is represented in ISO by the American National Standards Institute (ANSI). ISO operates through approximately 160 technical committees and 2,300 subcommittees that recommend standards and standardization policy to its national members. See also ANSI.

ISO 10160/10161

International communications standards that permit the exchange of ILL messages among ILL systems even if they use different hardware and software. The standards also control ILL transactions for both lending and borrowing activities. See also Direct Request.


An International Standard Book Number is a unique number assigned to a resource by its publisher. Each ISBN is a 10- or 13-digit number and has four parts: the language group of the country of publication, the publisher, the title, and the check character.


An International Standard Serial Number consists of eight digits in two groups of four, separated by a hyphen. ISSNs are assigned through the ISSN Network and are used to identify newspapers, journals, magazines, and periodicals of all kinds and on all media.


A unique document that is part of a serial that could be identified by words, numbers, or date of publication.


RDA defines an item as a single exemplar or instance of a manifestation.

A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  R  S  T  U  V  W Z



A periodical publication usually devoted to scholarly subjects.

A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  R  S  T  U  V  W Z



A file of keystroke shortcut assignments in Connexion client. Default key assignments are provided when you first install the client. You can customize keystrokes. Keymaps command on the Tools menu used to open windows for assigning, deleting, and working with keystroke assignments.

Keystroke shortcuts

Key combinations that let you perform actions using the keyboard rather than the mouse. You can use shortcuts to navigate the Connexion interface, take actions on records, view and navigate Help, edit records, insert diacritics and special characters, run macros, and navigate lists.


A word in a bibliographic record that is indexed. It often conveys subject content in a search for library resources. Keywords are found in titles, notes, abstracts, summaries, descriptions, and subjects. Keywords are also names of people and places that are the subjects of a library resource or a listing in a directory.

Keyword index

Default WorldCat search index (the system searches this index if a search has no specified index. Indexes a single word in a record, but other keyword search terms or qualifiers can be combined.

Keyword search

A type of search that uses a complete word, usually combined with other keywords.


A set of textual and nontextual materials in which no one material dominates and which has a collective title. For example, a workbook that comes with flashcards, worksheets, video recording, game board, playing pieces, and dice.

A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  R  S  T  U  V  W Z



Used on the spine of a book, on the pocket of a library item, or on a card representing a library item. See also Pocket label; Spine label.

Label content

The types of information to be included on labels, including location, sublocation, call number and enumeration.

Label file

A file created by catalogers using the OCLC Label Program (if using the Connexion browser) or using the Connexion client, which has a built-in label program.


Language of the text of the library resource. Also an index used to qualify WorldCat searches.


See OCLC Local Bibliographic Data (LBD).


See Library of Congress.

LC call number

See Library of Congress call number.


A Library of Congress Control Number (previously called a Library of Congress Card Number) is a unique number assigned to a bibliographic or authority record by the Library of Congress. Before January 2001, LCCNs consisted of a three-character prefix (often containing blanks), a two-digit year, a six-digit serial number, and a trailing blank. This number was often displayed with a hyphen separating the year and the serial number. After December 2000, LCCNs consist of a two-character prefix (often containing blanks), a four-digit year, and a six-digit serial number.


Library of Congress Rule Interpretations are cataloging guidelines issued by the Library of Congress that provide for a common practice, sometimes called "national" practice, in applying Anglo-American Cataloging Rules (AACR). This was the practice followed by the Library of Congress and all other libraries engaged in the bibliographic enterprise. These have been superseded by LC-PCC Policy Statements (LC-PCC PS), which are issued in conjunction with Resource Description & Access (RDA) guidelines.


See Library of Congress Subject Headings.


Lightweight Directory Access Protocol. An application protocol for querying and modifying directory services running over TCP/IP.


LDR may refer to either:


Data elements that provide information for the processing of the record. The data elements contain numbers or coded values and are identified by relative character position. The leader is fixed in length at 24 character positions and is the first field of a bibliographic, authority, and holdings record.


The library supplying the item.

Any institution lending something to you. You are the lending library when you supply something to another library.

Lender policies

Information about potential Lenders available from Find an OCLC Library and the OCLC Policies Directory.

Lender string

OCLC symbols of up to five potential lenders.

Less-than-full-level record

See Minimal-level records.

Level I standard

The OCLC input standard establishing criteria for a full or complete bibliographic record, indicated in a MARC record as ELvl:I. Level I is the equivalent of MARC 21 encoding level blank.

Level K standard

The OCLC input standard establishing criteria for a minimal level bibliographic record, indicated in a MARC record as ELvl:K. Level K is the equivalent of MARC 21 encoding level 7.


See OCLC Local Holdings Record Summary (LHRS).


See Institution.

Library identifier

A locally assigned code that represents a particular institution. The code appears in a local data field of a bibliographic record submitted for group processing. A translation table converts the library identifier to an OCLC symbol for a matched record. The OCLC symbol is set on matching records for "set holds" and removed from matched records on "cancels."

Library of Congress

The Library of Congress (LC) is located in Washington, D. C. and is the main research arm of the United States Congress. It is the home of the United States Copyright Office and serves as the nation's copyright depository. Although not officially a national library, it provides services appropriate to a national library.

Library of Congress call number

Identification number derived from the U.S. Library of Congress classification system. Used to retrieve a library resource.

Library of Congress Subject Headings

Library of Congress Subject Headings. An established list of preferred subject terms, selected by a subject specialist at the Library of Congress, from which an indexer or cataloger may select when assigning subject headings to a bibliographic record representing a work he/she is cataloging. Includes main terms and subdivisions.

Limited mode

A type of logon authorization generally used for training new catalogers. Those who log on to the system using a Limited authorization can search for and edit records and export them if needed, but cannot take final OCLC actions on records.

Literary form

A mode of literary expression such as poetry, drama, fiction, etc. Each form can be subdivided into kinds of forms, e.g., lyric poetry, comedy, science fiction, etc.

Local data

Data in a record that is pertinent only to the institution cataloging the record. For example, local processing information and cataloger's notes are local data. Certain 9xx fields are reserved for local data. Local data is not preserved in the WorldCat bibliographic record.

Local Data Record

See Local holdings record (LHR).

Local file

In Connexion client, the file that resides on your hard drive or a network drive at your library, not on the OCLC system. Local files are used to save bibliographic or authority records or to store bibliographic or authority constant data as you work in Connexion client. The client provides four empty default files for these purposes when you first install. You can create as many local files as you need.

Local Holdings Agent mode

An authorization mode that allows the Holdings Agent of a union list group to create and maintain local holdings records on a member's behalf.

Local Holdings Format

Metadata structure used to represent or share information about a library’s collection. The MARC 21 Format for Holdings Data is an example of a local holdings format. See also MARC 21 Format for Holdings Data; Local holdings record (LHR).

Local holdings maintenance

OCLC service that helps libraries maintain accurate, current holdings information by providing a library's holdings for materials in any format, including serials. Formerly called Union Listing.

Local holdings record (LHR)

Separate holdings record attached to a related WorldCat bibliographic record that provides holdings details for a particular library. These details include: copy-specific information for an item, information peculiar to the holding library, information needed for local processing, maintenance, or preservation of an item, and version information.

Local system

An institution's computer system that manages cataloging, acquisitions, circulation, serials and/or an online catalog. If elements of a local system are designed to interact, can be called an Integrated Local System (ILS).

Local system vendor

The company that manufactured a library's integrated library system.


An institution, a library within an institution, a library within a group of libraries, or a collection within an institution or library where a resource is stored or held.

Location information

A list of libraries that have used a bibliographic record for cataloging. Each bibliographic record in WorldCat has location information.

Locations record

See Holdings display.

Log off

The process of disconnecting from a local or remote system.

Log on

The process of connecting to a local or remote system.

A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  R  S  T  U  V  W Z


Machine-Readable Cataloging

See MARC (Machine-Readable Cataloging).

Macro recorder

In Connexion client, use to create a macro by recording actions in a procedure as you do them, whether you use the mouse to click commands or toolbar buttons, or press shortcut keystrokes, or use a combination of mouse and keyboard (Tools > Macros > Manage; click the Record button). The recorder writes the macro automatically in the OML macro editor. A good tool for those who prefer not to write their own macros.


Short programs you write using OCLC Macro Language and Connexion client-specific macro commands to automate routine cataloging tasks. Requires understanding of standard BASIC programming language.

Magnetic tape

A strip of flexible material coated or impregnated with magnetizable particles, upon which sound, images, and/or data can be written and stored. Magnetic tape is commonly found in reel-to-reel, cartridge, or cassette form. In the context of bibliographic, authority, and/or holdings data, magnetic tape was the usual file exchange medium before such exchanges could occur via the internet.

Main class

One of the ten major subdivisions of the DDC, represented by the first digit in the notation, e.g., 3 in 300 Social sciences.

Main entry

Under AACR2, the main entry is the primary access point for a resource. Most commonly, it is the person or corporate body with the chief intellectual responsibility for the resource. In other cases, the main entry is the title.

In the card catalog environment, the main entry was the card providing the most complete description of a bibliographic resource and listing all of the subject and secondary access points.


RDA defines a manifestation as a physical embodiment of an expression of a work.


A document (including musical scores, maps, as well as text) that is made by hand or transcripts.


See Maps format.

Maps format

OCLC-MARC Bibliographic format used to catalog cartographic material including maps, atlases, globes, digital maps, and other cartographic resources. The three-character format designator for cartographic material is "MAP".


See MARC (Machine-Readable Cataloging).

MARC (Machine-Readable Cataloging)

MARC (MAchine-Readable Cataloging) is a family of international standards for the representation and communication of bibliographic, authority, holdings, classification, and related information in machinereadable form, based upon the Format for Information Exchange, ISO 2709. MARC standards define the three elements of record structure, content designation, and data content. MARC 21, originally developed by the Library of Congress in the 1960s, is the most widely used of the MARC standards. UNIMARC (Universal MARC Format), developed by the International Federation of Library Associations and Institutions (IFLA) in the 1970s, is the second most widely used MARC standard. See also Communications format.


The version of Machine Readable Cataloging that superseded USMARC in 1999 with the harmonization of U.S. and Canadian MARC formats. MARC 21 is supported by OCLC and is the current official MARC standard in the United States, Canada, Australia, and numerous other countries.

MARC 21 Format for Authority Data

The MARC 21 Format for Authority Data defines the codes and conventions (tags, indicators, subfield codes, and coded values) that identify the data elements in MARC 21 authority records. It is a carrier for information concerning the authorized forms of names, titles, subjects, and subject subdivisions to be used in constructing access points, references to the authorized forms, and the interrelationships among these forms.

MARC 21 Format for Bibliographic Data

The MARC 21 Format for Bibliographic Data defines the codes and conventions (tags, indicators, subfield codes, and coded values) that identify the data elements in MARC 21 bibliographic records. It is a carrier for bibliographic information about printed, online, and manuscript textual materials, computer files, maps, music, continuing resources, visual materials, and mixed materials. Bibliographic data commonly includes titles, names, subjects, notes, publication data, and information about the physical description of a resource.

MARC 21 Format for Holdings Data

MARC 21 Format for Holdings Data defines the codes and conventions (tags, indicators, subfield codes, and coded values) that identify the data elements in MARC holdings reports for serial and nonserial resources. It is a carrier for holdings information for three types of bibliographic resources that are identified by a code in Leader/06 (Type of record). Holdings data commonly includes copy-specific information for an item, information that is peculiar to the holding organization, information that is needed for local processing, maintenance, or preservation of the item, and version information. See also Local Holdings Format; Local holdings record (LHR).

MARC organization code

Code assigned to libraries who participate in NACO (Name Authority Cooperative Program, the authority component of the Library of Congress's Program for Cooperative Cataloging). Allows users to add and replace authority records in the LC authority file.

MARC record

A MARC record is a representation of bibliographic, authority, holdings, classification, or related data in machine-readable form that is formatted according to the appropriate MAchine-Readable Cataloging (MARC) standard and may be used for data exchange. A single record collects data elements that describe or identify one or more units treated as one logical entity. The record consists of a leader, a directory, and variable fields. Variable fields are identified by a three-digit numeric tag and may include up to two numeric indicators supplying additional information about the field. Variable fields may be further divided into subfields identified by a single-character alphabetic or numeric code.

MARC-8 character sets

Approved character sets for MARC 21 cataloging as defined in MARC 21 Specifications for Record Structure, Character Sets, and Exchange Media. Subsets of Unicode. See also Non-Latin scripts; Unicode.

Master record

See WorldCat record.


The number of times the system identifies a search term, or the number of records retrieved as a result of a search.

Material type

The type of material the record represents. The type can represent a physical type, such as atlas or kit; or content, such as biography or fiction; or focus, such as juvenile or conference publication.

Material type template

See Workform.

Materials vendor

Wholesale booksellers and publishers who provide library materials through approval plans and firm orders from institutions.

Maximum field/record size

Bibliographic records must meet size limits defined in MARC21 standards. The number of characters in a field cannot exceed 9,999. The number of characters in a record cannot exceed 99,999. These limits apply to records you catalog using Connexion. The system capacity for a field in a record in WorldCat is 9,999 characters.

Media format

Indicates the physical form or the method of information delivery for a library resource described.

Medical Subject Headings

Formal and consistent vocabulary words and phrases used to describe the subject of a medical work. MeSH is provided by the National Library of Medicine for medical and health sciences libraries.

Meeting name

The name of a meeting, conference, exhibition, exposition, festival, athletic contest, scientific expedition, etc. used as an authorized access point in a bibliographic record.


See Medical Subject Headings.

Message file

A searchable file that groups your current ILL records according to status; a subset of the ILL Transaction File.


Literally, "data about data." Structured information describing information resources/objects for a variety of purposes. Although AACR2/MARC cataloging is formally metadata, the term is generally used in the library community for non-traditional schemes such as the Dublin Core Metadata Element Set, the VRA Core Categories, and the Encoded Archival Description (EAD). Metadata has been categorized as descriptive, structural, and administrative. Descriptive metadata facilitates indexing, discovery, identification, and selection. Structural metadata describes the internal structure of complex information resources. Administrative metadata aids in the management of resources and may include rights management metadata, preservation metadata, and technical metadata describing the physical characteristics of a resource.

Minimal-level records

Minimal-level records contain the essential data necessary to identify a resource. Generally, the records meet the requirements of AACR2 first-level description, rule 1.0D1. Minimal-level does not prohibit the addition of data deemed necessary.


See Mixed Materials format.

Mixed Materials format

OCLC-MARC Bibliographic format used for cataloging resources in two or more forms that are usually related by
virtue of their having been accumulated by or about a person or body. Includes archival and manuscript collections of mixed forms of materials, such as text, photographs, and sound recordings. It generally excludes resources whose primary purpose is instructional. The three-character format designation for mixed materials is "MIX". The mixed materials format was previously referred to as Archival and Manuscript Materials.


An aid used help memory. Fixed field elements of records have mnemonic identifiers to help catalogers with coding and interpretation.

Mnemonic label

An abbreviated identifier for an OCLC-MARC fixed field element, constructed from the full element name that it represents. The mnemonics are a display option in some WorldCat interfaces. For example, the mnemonics "ELvl" or "Enc Lvl" have stood for "Encoding Level."


A resource complete in one part or intended to be complete in a finite number of parts. See also Serial.

Multipart surname

Surname that includes prefixes, hyphenated names, or names that begin with articles or prepositions.

Music publisher name

See Publisher number.

Music publisher number

A formatted numbering designation assigned by a publisher to a music resource manifestation; these include plate numbers and publisher numbers for notated music and issue or serial numbers and matrix numbers for audio recordings. The phrase “Music Publisher Number” dates back to before field 028 was expanded for use beyond music and was still known as “Publisher Number for Music.”

Musical composition

Indicates the category under which a work of written or recorded music may fall based on its arrangement, structure, instrumentation, or other musical component.

My Status

In Connexion, a custom status you can assign to a saved records or constant data. Lets you enter up to 40 characters of free text (such as a name, identifier, or note) to help you identify, retrieve and manage records. If present, My Status appears in the status bar of a displayed record.

A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  R  S  T  U  V  W Z



Name Authority Cooperative Program (NACO), part of the Program for Cooperative Cataloging (PCC). Participants in NACO create and maintain authority records in the LC/NACO Name Authority File. See also PCC.

Name/title derived search

See Derived search.

National level enhance

See Enhance.


See NISO Circulation Interchange Protocol (NCIP).

NCIP unique user ID

Patron login credentials (i.e., library card number + pin) that are used to authenticate a patron via NCIP.

  • Borrower NCIP User ID: NCIP ID assigned to the borrowing library itself, used as the borrower when the patron ID or the lending library's ID is not available. For example, an item can be checked out to the borrowing library's ILL Department rather than to an individual or to the lending library's ILL Department.
  • Lender NCIP User ID: NCIP ID assigned to the lending library itself, used to check items out of their collection when the patron ID or the borrowing library's ID is not available. For example, an item can be checked out to the lending library's ILL Department rather than to an individual or that individual's library.

The Union List group symbol for the United States Newspaper Program.


Grouping terms within parentheses to specify the order in which they will be combined. Terms in the innermost parentheses will be combined and searched first. Without parentheses, terms will be combined in left-to-right order.


National Information Standards Organization. Accredited by ANSI (American National Standards Institute) to develop voluntary technical standards for the library, information sciences, and publishing communities.

NISO circulation interchange protocol (NCIP)

NISO standard defining messaging between circulation systems, Ill systems or broker applications. This protocol is limited to the exchange of messages between and among computer-based applications enabling them to:

  • perform functions necessary to lend and borrow items
  • provide controlled access to electronic resources
  • facilitate co-operative management of these functions
NISO standards

See ANSI/NISO Standards for Holdings Data.

Nonfiling indicator

In bibliographic and authority records, indicators determine the number of character positions associated with a definite or indefinite article (e.g., An, Le, or The) at the beginning of a title that are disregarded in sorting, indexing, and filing processes. Any diacritical mark, space, mark of punctuation associated with the article, and any space or mark of punctuation preceding the first filing character is included in the count of nonfiling characters.

Nongap break

In local holdings records, an indication that no issued items are missing, but a gap exists in the publication or numbering of the serial itself. For example, a change in enumeration of the series may cause a nongap break in the enumeration.

Non-Latin scripts

Character sets not based on Latin character sets. The Connexion client supports cataloging using all Unicode defined characters, which includes the following non-Latin, MARC-8 scripts: Arabic, Chinese, Cyrillic, Greek, Hebrew, Japanese, and Korean, as well as all of the UTF-8 Unicode character sets. See also MARC-8 character sets; Unicode.

Non-referral days

See System days.


Institution that does not respond to interlibrary loan requests through OCLC; OCLC symbols of nonsuppliers display in lowercase letters.


Statement in the note area of the bibliographic record giving information not included elsewhere in the bibliographic description. See also Note area.

Note area

The area following the physical description in a bibliographic record giving the contents of the work, its relationship to other works, and any physical characteristics not included in preceding areas of bibliographic description. Each note is given in a separate 500-590 field(s) in a MARC record. See also Note.

Numeric search

A type of WorldCat search that allows you to search for records by number, such as ISBN or OCLC control number.

A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  R  S  T  U  V  W Z



A union catalog of millions of records that was built by harvesting from open archive collections worldwide using the Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH).


Previously called Online Computer Library Center, Inc. and Ohio College Library Center. Nonprofit membership organization serving libraries around the world to further access to the world's information and reduce library costs by offering services for libraries and their users.

OCLC Authority File

A database that documents, for consistency, the authoritative forms of names (personal or corporate), titles, or subject headings to be used in a catalog from various authority files such as LC/NACO, Medical Subject Headings (MeSH), Dutch (NTA), Mori, and German (GND).

OCLC batchloading services

Automated method of processing bibliographic and local holdings records (LHR) submitted by libraries and vendors into WorldCat. (Separate service from cataloger-initiated batch processing in the Connexion client.) See also Bibliographic record; MARC 21 Format for Holdings Data.

OCLC catalog card

A 3" by 5" printed card containing bibliographic information. OCLC discontinued card production in 2015.

OCLC cataloging

OCLC's online services for cataloging library materials using WorldCat and for producing machine-readable records and other offline products. Participating institutions retrieve bibliographic records, modify the information for local use, and then order the modified record from OCLC. Institutions also contribute new records and location information to WorldCat for items for which no record is found. Access to cataloging activities is provided by the Connexion client, Connexion browser, CatExpress, and Z39.50 cataloging.

OCLC cataloging profile

Identifies and describes an institution's collections, including department and branch collections. Describes classification schemes and sources of subject headings.

OCLC CatExpress

An OCLC service for copy cataloging. CatExpress users log on from Connexion browser. Connexion users who also subscribe to CatExpress log on to Connexion and access CatExpress from the Express tab.

OCLC Connexion

Integrated cataloging service that offers access to WorldCat, the OCLC Authority File and other online databases. The browser interface provides access via Internet Explorer or other browsers. The client interface provides access via Microsoft Windows-based software installed on user workstations. Both interfaces offer the same cataloging capabilities. Each also provides unique capabilities. The browser interface uniquely provides access to CatExpress, Dewey services, local holdings maintenance, and OCLC Selection and supports creation of pathfinders and other electronic resources. The client uniquely supports the use of macros, local files, offline cataloging, integrated label processing, using non-Latin scripts for cataloging, and batch processing searches and record actions.

OCLC Connexion browser

One of two interfaces to OCLC Connexion cataloging services and products. Introduced in mid-2002, the Web-browser-based interface provides the same access to cataloging in WorldCat as the Connexion client. The browser interface also provides some unique functions, including WebDewey and Abridged WebDewey, CatExpress, OCLC Selection, Pathfinders and Local Holdings Maintenance.

OCLC Connexion client

One of two interfaces to OCLC Connexion cataloging services and products. Introduced in the second half of 2003, the Windows-based software interface provides the same access to cataloging in WorldCat as the Connexion browser. The client interface also provides some unique functions, including the use of macros and an automatic macro recorder, extensive keyboard shortcut customization, integrated label printing, local files, offline cataloging, batch processing for searches and record actions, use of non-Latin-based multiscripts for cataloging, and more.

OCLC control number (OCN)

OCLC control number (OCN) is a unique accession number assigned by the OCLC system when a bibliographic record is added to WorldCat. Used to search for records.

OCLC Customer Services Division (CSD)

OCLC's user assistance and support contact desk that provides support for telecommunications, hardware, and software.

OCLC distributor

An authorized agent for OCLC products and services for the international market. See also OCLC regional service provider.

OCLC holding library code

A four-character code that uniquely identifies a holding library within an institution that may be based on the institution's OCLC symbol. See also OCLC symbol.

OCLC Local Bibliographic Data (LBD)

Bibliographic information that is unique to the holding library such as local subject headings, uniform titles, or notes.

OCLC Local Data Record

See Local holdings record (LHR).

OCLC Local Holdings Record Summary (LHRS)

A concise description of all of a library’s local holdings for a specified title. Holdings summaries are most often used to provide a brief summary of a library’s serial or multipart holdings that are shelved at multiple locations.

OCLC New Jersey

Provider of a database that links metadata for electronic resources. Formerly known as Openly Informatics. Acquired by OCLC in 2006. Located in Bloomfield, New Jersey.

OCLC number

See OCLC control number.

OCLC Online Union Catalog (OLUC)

See WorldCat (the OCLC Online Union Catalog).

OCLC Policies Directory

Web-based repository of the copy and lending policies of libraries participating in WorldCat Resource Sharing. Information contained includes institution information (e.g., schedule, contacts, collections, web links), informational copy and lending policies, and deflection policies that allow requests to bypass an institution.

OCLC regional service provider

Centers organized by region or library type in the United States. Regional networks serve their libraries and library networks and provide access and support to OCLC members and participating library organizations that contract for OCLC services. See also OCLC distributor; OCLC-affiliated regional network.

OCLC Selection

A service that enhances the acquisition process by automating the processing of requests for library materials.

OCLC symbol

A unique, alpha-numeric 3- or 5-character identifier issued by OCLC to member institutions and participants. For example OCLC symbols are used in field 040 (Cataloging Source) in bibliographic records. See also Holding library code.

OCLC Union List

Former name for local holdings maintenance service. See also Local holdings maintenance.

OCLC usage statistics

Access reports on your library's use of OCLC services, including online cataloging. Available at

OCLC WorldCat Resource Sharing

Service that helps OCLC libraries borrow and lend materials through interlibrary loan. Facilitates creating, sending, managing and tracking loan requests and document orders.

OCLC WorldShare Collection Manager data sync collections

Automated method of processing bibliographic and local holdings records (LHR) submitted by libraries and vendors into WorldCat. Separate service from cataloger-initiated batch processing in the Connexion client.

OCLC-affiliated regional network

Centers organized by regions or library type in the United States. Regional networks serve their libraries and library networks and provide access and support to OCLC members and participating library organizations that contract for OCLC services.

OCLC-derived records

Bibliographic records originally obtained from OCLC. Some institutions export records directly from OCLC into their local system, without setting holdings online. These records are then returned to OCLC as a data sync collection to set and/or cancel the institution's holdings.


OCLC's implementation of the MARC bibliographic format. See also MARC 21 Format for Bibliographic Data.

OCLC-MARC format

OCLC's implementation of the MARC 21 format.


See OCLC control number.

Offline cataloging

Catalog in Connexion client without logging on to the OCLC system. Use local files to work on records offline. Prepare record actions and/or WorldCat or LC authority file searches to be batch processed.


See WorldCat (the OCLC Online Union Catalog).

Online error reporting

Various methods of reporting errors for bibliographic and authority records are available, depending upon the system used. For information on the methods of reporting errors, please see Bibliographic Formats and Standards (BFAS) 5.5, Requesting changes to records.


An acronym for online public access catalog, a database composed of bibliographic records describing the books and other materials owned by a library or library system, accessible via public terminals or workstations, or via the Internet. Most online catalogs are searchable by author, title, subject, and keywords and allow users to print, download, or export records to an Email account.

Open-ended holding

A holdings statement that indicates an item (such as a serial, a series, or a multipart work) is still in publication.

Original cataloging

Cataloging performed by an institution itself and not derived from any other source. Records produced by original cataloging might be matched in data sync processing.

A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  R  S  T  U  V  W Z


Parallel records

Records in WorldCat that describe a single resource, but which have been cataloged in different languages. For example, collation, notes, and subject headings are in different languages. See also Allowable duplicate records.


A sequence of characters required to gain access to a computer system. Usually used in conjunction with an authorization number. See also Authorization number; Default holding library code.


Pathfinders are subject-guide Web pages that libraries create to consolidate links to selected electronic resources on a topic. They categorize the resources, provide informative annotations, and integrate descriptions and locations for related resources available via the library but not web-accessible.

Connexion provides tools to help libraries create and manage pathfinders and to facilitate collaboration on pathfinder development and maintenance.


The Program for Cooperative Cataloging (PCC) consists of four programs (BIBCO, CONSER, NACO, and SACO). Libraries join this voluntary organization by becoming active in one or more of the programs. The Library of Congress houses the Secretariat of the PCC and is a PCC member. See also BIBCOCONSERNACOSACO.


Portable Document Format. The Adobe Acrobat standard that enables the same graphic display of a document on different platforms. Because the graphical display preserves hard-copy features such as page numbers, logical page breaks, tables of contents, etc., printing a PDF document makes a better hard copy than printing HTML-formatted documents. Most OCLC user documentation is available in PDF as well as HTML.


A magazine, journal, or other serial publication issued at regular, recurring intervals. Differs from a newspaper in format and publication frequency (annually, quarterly, monthly, weekly rather than daily).


Data or a display option that remains in effect until changed. For example, a holding library code persists until logoff unless changed by the user.

Personal name derived search

See Derived search.

Phrase indexes

Search indexes used to search for an entire field or subfield in records. Phrase indexes are also browsable.

Phrase search

Words, numbers, or character strings used to initiate a search for an entire field or subfield in a record. To enter a complete search string using a "command line" search in Connexion or an "expert" search in FirstSearch/Resource Sharing, use a phrase index label in the format xx=.

Example: To search for a personal name phrase, type pn=brooks, gwendolyn.

Physical description

Describes the physical characteristics of an item. For books, includes such data as dimensions, number of pages and illustrations, and accompanying materials, if any.


Originally a library cooperative in the Netherlands, serving that country as well as portions of Belgium, France and Germany. PICA was founded with half a million seed records from OCLC's catalog in 1979. In 1999, OCLC acquired a 35% portion of PICA, increasing that share to 60% in 2000. In July 2007, OCLC acquired the remaining 40% share from the Pica foundation.


In Connexion client, a method for keeping multiple records of the same type open simultaneously. Pinned command on the View menu used to pin the displayed record before opening another record of the same type (e.g., multiple online save file records or multiple WorldCat records).

Pocket label

A label listing title, author, and call number that is affixed to the inside pocket of a library item.

Policies Directory record

Record that contains name, address, interlibrary loan policy, and other communication information about an institution or unit of an institution. The OCLC Policies Directory replaced the Name-Address Directory as a repository for this type of information.


Originally, a general purpose Web site offering a wide variety of resources and services, such as news, weather, directory information, Web searching, free Email accounts, chat groups, mailing lists, online shopping, and links to other Web sites. However, the term is increasingly applied to Web sites that offer such services only within a particular industry, occupation, or field.

Post-processing report

Any number of reports generated as a result of data sync processing.

Precomposed diacritics

A single Unicode character that is a combined letter and diacritical mark(s) which also display as one character.

For example, the Latin small letter e with acute accent, é (U+00E9).

See also Diacritic; Decomposed diacritics.

Preferred title

A title forming the authorized access point that identifies a resource, especially if it has appeared under varying titles. Preferred titles generally serve one of two purposes: collocating versions of the resource including complete works, works in a particular literary or musical form (sonatas, songs) and distinguishing between different resources with the same or similar titles. Uniform title is the term used by AACR2, and Preferred title is the term used by RDA.

Processing center

An OCLC-defined arrangement whereby a single cataloging agent creates records or sets holdings in the online system under a single OCLC symbol for multiple institutions. Holding library codes identify the separate institutions. Holding library codes are retained in the online archive copy of bibliographic records, but only the OCLC symbol for the processing center appears in the holdings display of records. See also Cataloging Agent mode.

Processing report

See Post-processing report.


A structured definition of the content and format by a participating institution for OCLC products. During the profiling process OCLC assigns symbols to institutions.


An agent responsible for publishing, releasing, or issuing a manifestation.

Publisher number

Plate and publishers' numbers for printed music (scores); serial and matrix numbers for sound recordings; videorecording numbers for visual materials, and publisher numbers other than those for sound recordings, music, or videorecordings. The publisher number is located in field 028, subfield ‡a and is used for matching in data sync. For example, B 07042 L.

A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  R  S  T  U  V  W Z



A means of limiting a WorldCat search to specific classes of records, for example: type of material (index label - mt:), years of publication (index label - yr:), microform or not microform (index label - mf:), cataloging source (index label - cs=). Qualifiers are elements from the bibliographic record that are used in combination with a search term to narrow a search.

Qualify a search

A technique to make a search more precise by limiting results to specific classes of materials. Produces more manageable search results. See also Qualifier.

A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  R  S  T  U  V  W Z



See Resource Description & Access.


See Sound Recordings format.


A machine-readable record in a database that contains bibliographic information about a separately cataloged library item, set, or serial. A record can describe a book, journal article, or any other library resource, including electronic resources. It also contains coded information used to retrieve and work with data. In WorldCat, a bibliographic record is in OCLC-MARC format.

In the context of OCLC data sync processing, a record can be any amount of bibliographic data that represents a library item. The data can be minimal, as in a numeric search key, or more detailed, such as a bibliographic record.

Record matching

Computer system operation that compares one record to another based on search criteria to determine a match.

Record statuses

In Connexion, information stored with a saved record showing actions taken and whether they failed or succeeded, source of a record, custom-assigned My Status, position in cataloging workflow, and whether the record is edited.

Record structure

In MARC 21 formats, record structure is the order in which the content designators and content appear in the record and/or file. Record structure can include technical specifications used in the record and in files. The terms record format and record structure are often used interchangeably. See also Content designation.

Record type

Term that identifies the format, genre, or medium of a document for cataloging and for retrieving a specific type of record. Valid values vary by database. In FirstSearch/Resource Sharing searches, use the advanced or expert search screens to select a valid document type from the drop-down menu. In Connexion, type a full search in the command line of the Search WorldCat screen or window, or select from a dropdown list in the guided search area of the screen or window.


See WorldCat registry.

Report number

Uniquely identifies a technical report; not a series number. There are two kinds: Standard Technical Report Numbers and other nonstandard numbers.

Resolved record

A record that has been successfully processed through data sync either by matching to an existing record, including final action, or added to WorldCat.

Resource Description & Access

Also known as RDA. A current international standard used by libraries, archives, museums, and other cultural heritage institutions for describing materials of all types of content and media. A successor to AACR2, RDA is maintained in a collaborative process by the RDA Steering Committee (RSC). The RDA Toolkit is published by the American Library Association, the Canadian Federation of Library Associations, and Facet Publishing, the publishing arm of CILIP (the Chartered Institution of Library and Information Professionals).

Resource Sharing

See OCLC WorldCat Resource Sharing.

Review file

A file that acts as a "holding tank" for patron-generated ILL requests forwarded through external systems or set aside by you for further consideration.

Romanized data

Latin script representation of non-Latin script data in records.

A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  R  S  T  U  V  W Z



Subject Authority Cooperative program (SACO), one of the programs of the Program for Cooperative Cataloging (PCC). Participants in SACO submit proposals for Library of Congress Subject Headings (LCSH), for Library of Congress Classification (LCC), and for other LC vocabularies. The other vocabularies are LC Genre/Form Terms (LCGFT), LC Demographic Group Terms (LCDGT), and LC Medium of Performance Thesaurus for Music (LCMPT). See also PCC.


Standard Address Number. A unique seven-digit identifier used to signify a specific address of an organization in (or served by) the publishing industry. Initiated by R. R. Bowker, the SAN is an American National Standard.

Save file

In Connexion, a temporary online storage area for bibliographic or authority records that catalogers are in the process of creating, editing, reviewing, etc. Each library has a single online save file per logon authorization that is accessible to catalogers from that library only.

In the Connexion client only, catalogers can also use local save files while logged on or offline ("local" means that they are stored on a workstation or shared drive).

Online and local save files can store up to 9,999 records.

Save file number

The number the system uses to track records in your library's cataloging Save file.


Command used to send a browse string to the system to scan indexes. See also Browse.


(1) Listings of subjects and their subdivisions arranged in a systematic order with notation given for each subject and its subdivisions. (2) The series of DDC numbers 000–999, their headings and notes.

SCIPIO record

SCIPIO = Art and Rare Book Sales Catalogs. SCIPIO records cover art auction and rare book catalogs for sales from the late sixteenth century through the present. SCIPIO records were incorporated into WorldCat during the integration of RLG (Research Libraries Group) into OCLC.


See Scores format.

Scores format

OCLC-MARC Bibliographic format used for cataloging notated music, which may consist of graphical, symbolic, or word-based musical notation in manuscript, printed, microform, or electronic form; the three-character format designator for scores is “SCO”.

Search history

In a Connexion Search WorldCat screen or window, search term input boxes have a popup or dropdown list that displays up to 10 previous searches.

Search key

In Connexion client only, a search entered in command line format (full search syntax) and add to a list stored in a local file for batch processing.


The process of retrieving records from a database.


One part of a derived search. See also Derived search.


See Serial.


A continuing resource issued in a succession of discrete parts, usually bearing numbering or chronological designations, that is intended to continue indefinitely. Includes annuals, journals, newspapers, numbered monographic series, periodicals, proceedings, etc. The three-character format designator for serial is "SER". See also Monograph.

Serials format

See Continuing Resources format.


A group of separate resources related to one another by the fact that each resource bears, in addition to its own title proper, a collective title applying to the whole. The individual resources may or may not be numbered. Series may include monographic series, another type of serial, multipart monographs, and integrating resources.

Series title

The collective title of all items in a series, as opposed to each item's individual title. A series title represents the name of a group of separate resources related to each other by subject matter, issued successively, and generally by the same publisher in a uniform style, with each resource having, in addition to its individual title, a collective series title.


Series title—Summer Institute of Linguistics Publications in Linguistics

Title (of individual item in series)—Modes in Denya Discourse

See also Title.


Time between logon and logoff when an OCLC library is logged on to the OCLC system to use a production or service.

Set holdings on a record

OCLC member libraries "set" their holdings by attaching their OCLC symbols to bibliographic records in WorldCat. Having OCLC symbols attached to a record establishes that the institution holds the item.

Set of records

A group of records viewed when 1) a search retrieves multiple records or 2) a display of multiple records is requested.


See FTP.

Shared local catalog

A catalog containing the records from several libraries.


Items that come to the institution from the materials vendor with labels affixed and ready to be put into the collection.

Sound Recordings format

OCLC-MARC Bibliographic format used for cataloging musical and non-musical audio recordings; the three-character format designator for sound recordings is “REC”.


See Cataloging source.

Source status

Designates the source of a displayed record in Connexion: Derived, Extracted, Imported, Workform, OCLC, Pathfinder, URL. Source status is system-assigned and appears in the status bar of a displayed record.

Special character

Graphic characters and diacritics other than those used in the Latin alphabet. See International Cataloging: Use Non-Latin Scripts and BFAS 2.7 Character Set for more information. See also Diacritic.

Spell checker

A Connexion client tool to check spelling in a record.

Spine label

The label affixed to the spine of a library book.


See Cataloging Source.

Status bar

In Connexion client, shows status information at the bottom of a record or list or main client window. Stored only in the working copy of saved records, except for Report Error status. Not retained in the WorldCat record.


See Record statuses.


Words to be omitted from a search because they are so common that they have no informational value. Stopwords are not indexed and are therefore ignored by the system if entered in a search. See stopword lists in the Help for Connexion or the Help for FirstSearch/Resource Sharing. Examples: a, an, and, or, and the.


The smallest logical unit of information in a MARC variable field. Subfield codes (letters or numbers) identify subfields and are preceded by subfield delimiters (‡ or $). In OCLC cataloging interface displays, a subfield ‡a is implicit at the beginning of most fields, but does not display. See also Subfield delimiter.

Subfield delimiter

Character (‡ or $, depending upon the OCLC cataloging interface display) followed by a single letter or number code, used to define the beginning of a subfield within a variable field in a MARC bibliographic or authority record. See also Subfield.


The topic treated, or matter discussed, in a resource. What a resource is about. Subject schemes (for example, Library of Congress Subject Headings [LCSH]) use a controlled vocabulary to categorize library materials about the same subject.

Subject headings

The most specific word or phrase that describes the subject, or one of the subjects, of a work, selected from a list of preferred terms (controlled vocabulary) and assigned as an added entry in the bibliographic record to serve as an access point for retrieving records in a database.

A subject heading may be subdivided by the addition of subheadings (example: Libraries--History--20th century) or include a parenthetical qualifier for semantic clarification, as in Mice (Computers).

The use of cross-references to indicate semantic relations between subject headings is called syndetic structure.

The process of examining the content of new publications and assigning appropriate subject headings is called subject analysis.

Subject scheme

Subjects categorize library material and provide controlled access to the content of resources. Schemes define concepts and relationships between concepts to support user navigation. Subject schemes, such as Library of Congress Subject Headings (LCSH), use a controlled vocabulary; that is, they use the same terms to categorize the library material about the same subject. For example, a resource about atomic structure and another resource about neutrons can have the same subject entry, Nuclear physics.


A word, character(s), or phrase that appears in conjunction with, and is subordinate to, a title proper of a manifestation. Also known as other title information.

For visual materials, a subtitle is text displayed at the bottom of a moving image expression that is a translation, transcription, or paraphrase of the dialogue or narrative.


An institution that supplies items requested via OCLC WorldCat Resource Sharing. The institution's interlibrary loan polices may determine what items the institution supplies via WorldCat Resource Sharing.


A name used as a family name that may precede or follow a given name, depending on the culture. See also Given name.

System days

In OCLC WorldCat Resource Sharing, days that exclude Saturdays, Sundays, OCLC-observed holidays, or other days when interlibrary loan is unavailable; also known as "Non-referral days." OCLC does not count Saturdays, Sundays and the following as working days for aging requests:

  • New Year's Day
  • Thanksgiving Day
  • Day after Thanksgiving
  • Christmas Eve
  • Christmas Day
  • New Year's Eve

See also Calendar days.

A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  R  S  T  U  V  W Z



A 3-character string used to identify or label an associated MARC field. Tags are grouped numerically by function. See also Tag group.

Tag group

MARC tags beginning with and grouped by the first digit according to function. For example, 1xx tags are primary access points, 2xx tags are titles, 3xx tags are for physical description, and so on.


See Magnetic tape.


Transmission Control Protocol/Internet Protocol. A set of computer programs that enables communication between similar or dissimilar computers on a network. Internet Protocol is the standard for sending data on the Internet.


The type matter on a page or in an electronic document that is distinct from illustrations or graphics.

Text strings

Often used data to insert into records over and over. Shorter version of constant data.


A word, phrase, character, or group of characters, normally appearing on a resource, that names the manifestation or the work contained in it. See also Series title.

Title derived search

See Derived search.


Represent data in one script in the corresponding characters of another script in records.

Truncated list

In Connexion client, the default display of WorldCat search results when a search retrieves 6 to 100 records.

Truncation (*)

Truncation allows you to search for a term and its variations by entering only the root of the term or phrase followed by an asterisk *. Use the truncation symbol only at the end of a term. See also Wildcard (# or ?).

Type of material (format) qualifier (ft)

Qualifier that limits search results to specific formats: books (BKS), computer files (COM), maps (MAP), mixed materials (MIX), continuing resources (CNR), scores (SCO), sound recordings (REC), or visual materials (VIS.

Type of Record (Type)

The element in the fixed field that differentiates records created for various types of machine-readable information and specific types of material. Codes used in Type of Record are also used in field 006.

A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  R  S  T  U  V  W Z


Unabridged edition

See Full edition.


A worldwide character encoding standard allowing processing, storing, and data exchange in any language or script. Unicode includes symbols, punctuation, and other characters such as diacritics in addition to textual characters. UTF-8 (Unicode Transformation Format 8 bit) is a term often used within the MARC context to refer to Unicode. UTF-8 is a variable-width character encoding capable of encoding all valid character code points in Unicode using one to four one-byte (8-bit) code units and is the most common encoding used for the World Wide Web. See also Non-Latin scripts; MARC-8 character sets.

Uniform title

Uniform title is the term used by AACR2, and Preferred title is the term used by RDA. See Preferred title.

Union catalog

A list of the holdings of all the libraries in a library system. Also, a listing of all or a portion of the collections of a group of independent libraries, indicating by name and/or location symbol which libraries own at least one copy of each item. When the main purpose of a union catalog is to indicate location, the bibliographic description provided in each entry may be reduced to a minimum, but when it also serves other purposes, description is more complete. The arrangement of a union catalog is normally alphabetical by author or title.

Union list

A complete list of the holdings of a group of libraries of materials (1) of a specific type, (2) on a certain subject, or (3) in a particular field, usually compiled for the purpose of resource sharing. The entry for each bibliographic item includes a list of codes representing the libraries owning at least one copy. Union lists are usually printed, but some have been converted into online databases.

Union list custom holdings location

A record of a preferred lender that identifies specific volumes of serials and journals held by an institution; more complete than bibliographic locations records.

Unique-key matching

A data sync procedure that matches records by field 035 (OCLC control number). Also known as Numeric Search Key.

Unresolved record

A record that failed to match any database record after being processed by the matching algorithms of OCLC data sync services and is added to the database via data sync processing as unindexed. The record is only discoverable using the OCLC control number search. Institutions receive a report of these OCLC control numbers via an Unresolved Cross Reference File.

Updating loose-leaf

An integrating resource that consists of one or more base volumes updated by separate pages that are inserted, removed and/or substituted.


Uniform Resource Locator. Address or location of a Web page or other electronic resource.

User profile

Defines all Connexion client settings, including those for logging on, local files, options, toolbars, customized keystroke shortcuts and text strings, session information, and more. Creating more than one user profile facilitates cataloging for more than one library (cataloging agents).


See Unicode.

A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  R  S  T  U  V  W Z


Validate a record

Examine the data in certain fields for consistency and compliance with various rules via the Validate (val) command. The system also performs automatic validation on records when you Replace, Produce, Update, or Delete Holdings.

Validation error

An error in the MARC format of a record as detected by OCLC system validation. Examples of validation errors include: invalid codes, tags, indicators and subfields, missing required elements, and repetition of non-repeatable fields. See also Error rate.

Variable field

Any variable field other than a MARC 00x control field. Each variable data field has a tag identifier, indicators, and subfields preceded first by a delimiter (‡ or $) and then by a single letter or number subfield code. Some variable fields may occur only once in a record; others can be repeated. Length of field data is variable. MARC 21 standards require that the number of characters in a field not exceed 9,999. See also Subfield.

Varying form of title

A title or portion of the title associated with the resource recorded in the MARC 246 field. It differs from the title proper and contributes to discovery and identification of the resource.


A resource sharing option for library groups that need greater local control of resource sharing with tight integration to local library systems. It builds on the foundation of OCLC's existing services for groups that include cataloging, resource sharing, reference and digitization services.


See Local system vendor; Materials vendor.

Vendor-provided data

Information sent by the vendor partner in the vendor manifest that is added to the bibliographic records provided to institutions, such as barcodes, invoice numbers, invoice dates, and prices.


See Visual Materials format.

Visual Materials format

OCLC-MARC Bibliographic format used for cataloging projected media, non-projected media, two-dimensional graphics, three-dimensional artifacts or naturally occurring objects, and kits; the three-character format designator for visual materials is “VIS”.

A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  R  S  T  U  V  W Z


Web Harvester

An OCLC service that captures, manages and provides access to born-digital, Web-based content. Enables catalogers using the OCLC Connexion client (version 2.1+) to harvest content from the Web, review it and then add the harvested items to their CONTENTdm collections during the Connexion cataloging process.


A service for assigning Dewey Decimal class numbers in records for library items.


An online community dedicated to the emerging technology and training needs of librarians. Originally created by the Bill & Melinda Gates Foundation's U.S. Library Program, with OCLC and other partners.


Entities from Functional Requirements for Bibliographic Records (FRBR) that represent the products of intellectual or artistic endeavors used in RDA that stands for Work, Expression, Manifestation, Item. See also WorkExpressionManifestation; Item.

Whole phrase index

Search indexes used to search for entire indexed fields of records. Whole phrase indexes are also browsable.

Whole phrase search

All words, numbers, or character strings used to initiate a search for an entire indexed field in records. To enter a complete search string using a "command line" search in Connexion, use a whole phrase index label in the format xxw= (where xx represents the label).

Note: FirstSearch/Resource Sharing supports only one whole phrase index—Subject. This index label has a different format; see example below.

For a whole phrase search, enter all field data or truncate using an asterisk.


  • To search for a subject field in Connexion, type suw=library science computer* (field data is truncated).
  • To search for the same subject field in FirstSearch/Resource Sharing, type sa=library science computer* (field data is truncated).
Wildcard (# or ?)

A special character used to represent one or more characters in a search term. The pound sign (#) represents a single character, and the question mark (?), alone or with a number, represents zero or more characters. Wildcards must be preceded by at least three characters in a term. Example: wom#n retrieves women or women; col?r retrieves color or colour. See also Truncation (*).


For searching purposes, any character or group of characters between two blank spaces, including initials or abbreviations.

Word indexes

Search indexes used to search for a word or number in specific indexed fields of records. Word indexes are also browsable.

Word search

A word, number, or character string used to initiate a search for a word in an indexed field in records. To enter a complete search string using a "command line" search in Connexion or an "expert" search in FirstSearch/Resource Sharing, use a word index label in the format xx:.

Example: To search for an OCLC control number, type no:10998406 (or #10998406 or *10998406).

Word-by-word alphabetization

Refers to the filing of entries word by word, not letter by letter. For example, New York files before Newark in word-by-word alphabetization; Newark files before New York in letter-by-letter alphabetization.


RDA defines a work as a distinct intellectual or artistic creation, that is, the intellectual or artistic content. The term work can refer to an individual work, an aggregate work, or a component of a work.

Work mark

The part of a book number that consists of a letter appended to the author (or biographer) designation to show the first letter of the title (or first letter of the surname of the biographer). See also Book number.

Workflow status

In Connexion client, designates a record's position in your cataloging workflow. You select from a system-supplied list: Completed, In Process (default), In Review, or New. Displays in the status bar of a record.


An OCLC-MARC template used to create an original record or local holdings record in Connexion, also known as material type template in Record Manager. The system automatically supplies some of the appropriate fields and data, depending on the format you select for the resource you are cataloging.

Working copy

A copy of the WorldCat record, displayed on the user's screen. When the user edits the working copy, the WorldCat record remains unchanged. Also called "editing locally."

WorldCat (the OCLC Online Union Catalog)

An online database of records cooperatively built from the bibliographic and ownership information of OCLC contributing libraries. The WorldCat database is the largest and most comprehensive of its kind. WorldCat is the foundation of many OCLC services that enable institutions to process, manage, and share information resources, including cataloging, resource sharing, reference, discovery, collection evaluation, and local holdings. WorldCat consists of three major components: a bibliographic catalog that includes everything available to library users, a knowledge base that connects library users to electronic content, and a registry of library profiles that allows libraries to maintain information about their services. The first bibliographic records were added to WorldCat in 1971. Until being rebranded as WorldCat in 1997, it was known as the OCLC Online Union Catalog (OLUC).

WorldCat Link Manager

OpenURL linking and listing service that allows users to link from an article citation in WorldCat to the full-text version of the article.

WorldCat Local

An OCLC service that interoperates with existing locally maintained services to provide high-level Web visibility for a library's collection. It uses the interface to provide Web access to WorldCat. It provides the first step toward cooperative, Web-scale library management services.

WorldCat Navigator

An OCLC service that provides seamless resource sharing within a library consortium. The service manages returnable and nonreturnable items, and integrates with internal circulation systems and the wider OCLC resource sharing network to create a unique discovery-to-delivery service.

WorldCat record

The bibliographic record available to all OCLC cataloging users for copy cataloging. By policy, WorldCat contains only one WorldCat record per manifestation for each language of cataloging. Previously called the Master record, the WorldCat record does not include local data.

WorldCat registry

An online global directory of libraries, their locations, and the services they provide.

WorldCat Resource Sharing

See OCLC WorldCat Resource Sharing.

WorldCat Search API

Provides access to WorldCat bibliographic records and holdings using the FRBR concepts to pull together various editions of the same work. The API provides access to the WorldCat databases from clients that can send RESTful URI queries with either the OpenSearch or SRU protocols and can accept RSS, Atom, MARC XML or Dublin Core® responses.

OCLC service that allows users to access WorldCat through a search box that can be included in a variety of web sites. Users can them find the items in a library near them or buy them directly.

A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  R  S  T  U  V  W Z



A client-server protocol established as a NISO standard that allows the computer user to query a remote information retrieval system using the software of the local system and receive results in the format of the local system. Often used in portal and gateway products to search several sources simultaneously and integrate the results.

Z39.50 Cataloging

An OCLC service that enables libraries to use the Z39.50 interface to access WorldCat in order to search and retrieve MARC records for cataloging.


  • Was this article helpful?