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Data sync processing glossary

Find a comprehensive listing of data sync processing terms accompanied by definitions.

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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 institutions end.

allowable duplicate records

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


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.

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See National bibliographic agency control number.

batch processing

See batchloading.


A process by which records to be processed are collected into batches. The records in a batch are loaded all at once.


BIBFRAME (Bibliographic Framework) is a data model for bibliographic description. BIBFRAME was designed to replace the MARC standards, and to use linked data principles to make bibliographic data more useful both within and outside the library community. Data sync uses this data model for processing Bibliographic and Delete WorldCat Holdings collections.

bibliographic record

Contains the cataloging information that describes the physical format and intellectual content of a single entity (a book, video, computer file, CD, etc.). Catalogers create records by encoding this information using tags, indicators, and subfield codes in a standard format called MARC 21 (MAchine-Readable Cataloging). Each record is divided into fields (author, title, subjects, etc.). Fields are subdivided into subfields (place of publication, publisher, etc.).

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.

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See delete.

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.

Designación CODEN

The Chemical Abstracts Service assigns six-character Coden Designations to serials. The first four characters are letters and have a mnemonic relationship to the serial. The fifth character is either A, B, C, or D. The sixth character is an alphabetic or numeric check character. For example, AISJB6, CADIDW. The Coden Designation is located in field 030, subfield ‡a and can be used during data sync matching.

Identificación de la colección

Unique seven-digit number generated when a data sync collection is saved or submitted. It is used in an institution's filename to identify the appropriate data sync collection for processing.

Collection Types

The following collections are considered Data Sync Collection Types: Bibliographic, Local Holdings Records, Bibliographic and Local Holdings Records, Delete WorldCat holdings, Delete Local Holdings Records, and MARC or Non-MARC (data type). Subsets are: Group, WMS, and Vendor.

communications format

In machine-readable cataloging (MARC), the standards for representation and exchange of data in machine-readable form. In the USA, this is an implementation of an ANSI standard. MARC 21 Format for Bibliographic Data (formerly called USMARC) is an implementation of ANSI standard Z39.2. OCLC-MARC is an implementation of MARC 21 that conforms to the ANSI standard. Standards provide a common way of organizing machine-readable records so that they can be easily exchanged among users.

content designation

In machine-readable cataloging (MARC), the codes and conventions established to identify and characterize the data elements within a record and to support manipulation of that data. OCLC defines content designation for OCLC-MARC records in OCLC Bibliographic Formats and Standards, Authorities User Guide, and Union List User Guide.

content of the record

The data in the MARC records. The content is defined by standards outside the format, such as Anglo-American Cataloguing Rules, Library of Congress Subject Headings, ANSI/NISO Standards for Serials Holdings Statements or other rules and codes used by the organization that creates the record. See also record structure; content designation.


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

Cross reference report(s)

A post-processing report generated for each data sync file processed. This report lists the institution's unique record identifier and the OCLC number for the matching WorldCat record. This report is generated for both resolved and unresolved records. Also referred to as the Bibliographic Cross Reference File and/or the Unresolved Cross Reference File, respectively; also known as xrefrpt or unresxrefrpt.


See OCLC Customer Services Division (CSD).

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Data Sync Collection Profile

The specifications for an institution's OCLC data sync collection. The data sync collection profile details the general properties about the collection, 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 also OCLC WorldShare Collection Manager data sync collections.

Data sync record analysis

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.

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.


See duplicate detection and resolution.


Selections predetermined by the computer or an application on the computer in the absence of specific selections made by the user.

Elements supplied in the bibliographic or local holdings record by subroutines in preprocessing for missing or invalid values. Defaults are only supplied to enable processing or to aid in accurately matching the record.


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.


Character (‡), 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.

For data sync, the delimiter is represented by a dollar sign ($).

Dublin Core

An international standard that supports creation of simple, information descriptions of electronic resources that facilitates 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 (DDR)

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.

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error rate

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

eSerials Holdings Service

OCLC service that sets and maintains title level holdings for electronic serials in WorldCat.


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 collection.

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.

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file analysis

See Data sync record analysis.


Unique name given to a file of records sent for a specific collection. The filename follows the set of data all the way through processing up to and including reporting

file transfer protocol (FTP/(sFTP))

File Transfer Protocol (FTP/(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 through your OCLC allocated directory. 

Fingerprint matching

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

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 file transfer protocol (FTP/(sFTP).

full member

An OCLC general member that contributes current cataloging and holdings to WorldCat.

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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.

group data sync collection

Data submitted on behalf of multiple libraries in a single file for data sync processing. Processing options for group collections differ slightly from those for single-institution collections.

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holding library

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

holding library code

See OCLC holding library code.

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

institution symbol

See OCLC symbol.

integrated local system (ILS)

See local system.

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.

Número internacional normalizado de publicaciones seriadas (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.

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See local holdings record (LHR).

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".

Número de control de la Biblioteca del Congreso

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.

live data

Data to be used for setting and canceling OCLC symbols and not merely for evaluation.

local holdings record (LHR)

The OCLC record used to contain and exchange holdings data for WorldCat records. Local holdings records form the basis for local holdings displays. The records are based on the MARC 21 Holdings format.

The OCLC record used to contain and exchange holdings data. It can record both institution (SIHD) and copy (SCHD) holdings 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, it can be called an Integrated Local System (ILS).

local system vendor

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

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Machine-readable cataloging



Machine-Readable Cataloging. An international standard digital format for the description of bibliographic items developed by the Library of Congress during the 1960s to facilitate the creation and dissemination of computerized cataloging from library to library within the same country and between countries. By 1971, the MARC format had become the national standard for dissemination of bibliographic data and by 1973, an international standard.

Several versions of MARC are in use internationally, the most predominant of which is MARC 21, created in 1999 as a result of the harmonization of U.S. and Canadian MARC formats. UKMARC is used primarily in the United Kingdom. UNIMARC is widely used in Europe. Besides formats for bibliographic records, the MARC 21 family of standards now also includes formats for authority records, holdings records, classification schedules, and community information.

MARC 21 Format for Bibliographic Data

The format for printed and manuscript textual materials, computer files, maps, music, continuing resources, visual materials, and mixed materials. Bibliographic data commonly include titles, names, subjects, notes, publication data, and information about the physical description of an item. See also OCLC-MARC.

MARC 21 Format for Holdings Data

The format for representation and exchange of holdings data from the Library of Congress.

MARC record


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National bibliographic agency control number

The unique numbers assigned to a record by a national bibliographic agency other than the Library of Congress. These numbers are record control numbers used in a national bibliographic agency system and are coded in field 016, subfield ‡a. They are unique keys that can be used during data sync processing.

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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 control number

A unique accession number assigned by the OCLC system when a 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. Formerly called OCLC User and Network Support (UNS).

OCLC holding library code

A unique code that identifies a holding library within an institution. See also OCLC symbol.

Símbolo de OCLC

A unique identifier assigned by OCLC to member libraries and other participants. OCLC symbols in records and in holdings displays identify libraries that have entered, modified, and used the bibliographic records for cataloging. See also OCLC holding library code.

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. See bibliographic record, MARC 21 Format for Holdings Data.

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.


ONIX (publishing protocol) (ONline Information eXchange) currently refers to any of three XML standard metadata formats developed by EDItEUR for use primarily within the book trade. This data is crosswalked into an acceptable format before it is used in data sync processing.

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.

other standard identifier (OS#)

Standard numbers or codes published on an item that cannot be accommodated in another field (fields 020, 022, 027, etc.). Use the first indicator or subfield ‡2 to indicates the type of number or code. This number is located in field 024, subfield ‡a and is used for matching in data sync.

other system control number (OSCN)

OCLC uses field 029, subfield ‡a for system control numbers for records from non-OCLC automated systems (e.g., Library and Archives Canada, the British Library, vendors, etc.). OCLC uses these numbers (when processing) to track records from other systems. They are used in matching within data sync.

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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.


Program for Cooperative Cataloging. An international cooperative project. PCC includes BIBCO (monographic bibliographic component), CONSER (Cooperative Online Serials Program, the serials bibliographic component), NACO (name authority component), and SACO (subject authority component). For more information, see Program for Cooperative Cataloging.

Post-processing report

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

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.


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

project coordinator

The person responsible for acting on behalf of a number of administratively separate institutions involved in a group data sync collection. The project coordinator is the main contact with OCLC for all aspects of the collection throughout its duration.

publisher number

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

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See Resource Description and Access.


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 structure

The order in which content designators and content appear in the record and/or file. Record structure can include such specifications as tape media, header, blocking techniques, and characters sets. The terms record standard and record structure are used interchangeably. See also content designation; content of the record.

número de informe

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 and Access

This is a standard for descriptive cataloging initially released in June 2010, providing instructions and guidelines on formulating bibliographic data.

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scan/delete processing

An offline process that cancels an institution's OCLC symbol from all bibliographic records and deletes all local holdings records for that institution. This process is not reversible, nor is any record of the deletion retained or written to an archive. The process is used only when an institution closes permanently. At the end of a reclamation, a scan/delete can be performed with a cut-off date so that only holdings not updated or added after that date are removed.

set hold

The attachment of an OCLC symbol to a bibliographic record through data sync.

single-institution collection

A data sync collection defined for a single institution.


The smallest unit of information in a variable field. Data in subfields is preceded by a delimiter (‡) and a single letter or number code. A subfield a (‡a) is implicit at the beginning of most fields. The delimiter and code do not display. See also delimiter.

subfield delimiter

See delimiter.

symbol merge

A one-time process to convert institution holdings from one or many OCLC symbols to another OCLC symbol.

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translation table

A table used for converting holding library codes or other local library identifiers to OCLC symbols.

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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.

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.

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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.

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A database of online records built from the bibliographic and ownership information of contributing libraries. The WorldCat database is the largest and most comprehensive of its kind. OCLC members use WorldCat for a full array of technical library services, including cataloging, interlibrary loan, reference, union listing, local holdings, and many more. WorldCat is the foundation of many OCLC services that let your library process, manage and share information resources. And with its records now opened to Web search, bookselling and bibliography sites, holdings in your collection are even more easily located and obtained by both your local patrons and a broad-based Internet usership.

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See Cross reference report(s).

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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.