MARC standards
Encyclopedia
MARC, MAchine-Readable Cataloging
Cataloging
Cataloging is the process of listing or include something in a catalog. In library science is is the producing of bibliographical descriptions of books or other kinds of documents...

, is a data format and set of related standards used by libraries to encode and share information about books and other material they collect. It was first developed by Henriette Avram
Henriette Avram
Henriette Davidson Avram was a computer programmer and systems analyst who developed the MARC format , which is the national and international data standard for bibliographic and holdings information in libraries...

 at the Library of Congress
Library of Congress
The Library of Congress is the research library of the United States Congress, de facto national library of the United States, and the oldest federal cultural institution in the United States. Located in three buildings in Washington, D.C., it is the largest library in the world by shelf space and...

 in the 1960s, and is still widely used today as the basis for most online public access catalogs.

MARC record structure and field designations

The MARC standards define three aspects of a MARC record: the record structure, the field designations within each record, and the actual content of the record itself.

ISO 2709

MARC records are typically stored and transmitted as binary files, usually with several MARC records concatenated together into a single file. MARC uses the ISO 2709
ISO 2709
ISO 2709 is an ISO standard for bibliographic descriptions, titled Information and documentation—Format for information exchange.It is maintained by the Technical Committee for Information and Documentation .-History:...

 standard to define the structure of each record. This includes a marker to indicate where each record begins and ends, as well as a set of characters at the beginning of each record that provide a directory for locating the fields and subfields within the record.

MARC-XML

In 2002, the Library of Congress developed the MARC-XML schema as an alternative record structure, allowing MARC records to be represented in XML. Libraries typically expose their records as MARC-XML via a web service
Web service
A Web service is a method of communication between two electronic devices over the web.The W3C defines a "Web service" as "a software system designed to support interoperable machine-to-machine interaction over a network". It has an interface described in a machine-processable format...

, often following the SRU
Search/Retrieve via URL
Search/Retrieve via URL is a standard search protocol for Internet search queries, utilizing Contextual Query Language , a standard query syntax for representing queries.-External links:* at Library of Congress...

 or OAI-PMH standards.

Field designations

Each field in a MARC records provides information about the item the record is describing. Since it was first developed at a time when computing power was low, and space precious, MARC uses a simple three-digit numeric code (from 001-999) to identify each field in the record. The bibliographic standard, for example, defines 100 as the primary author of a work, 245 as the title, 260 is used for publisher information, and so on.

Fields above 008 are further divided into subfields using a single letter or number designation. The 260, for example, is further divided into subfield 'a' for the place of publication, 'b' for the name of the publisher, and 'c' for the date of publication.

Content

MARC is a metadata transmission standard, not a content standard. Other than a handful of fixed fields defined by the MARC standards themselves, the actual content a cataloger will place in each MARC field is usually governed and defined by standards outside of MARC. The Anglo-American Cataloguing Rules, for example, define how the physical characteristics of books and other item should be cataloged. The Library of Congress Subject Headings
Library of Congress Subject Headings
The Library of Congress Subject Headings comprise a thesaurus of subject headings, maintained by the United States Library of Congress, for use in bibliographic records...

 (LCSH) provides a list of authorized subject terms to describe the main content of the item. Other cataloging rules, subject thesauri, and classification schedules can also be used.

MARC 21 allows the use of two character sets, either MARC-8
MARC-8
The MARC-8 charset is a MARC standard used in MARC-21 library records. The MARC formats are standards for the representation and communication of bibliographic and related information in machine-readable form, and they are frequently used in library computer systems. The encoding now known as...

 or Unicode
Unicode
Unicode is a computing industry standard for the consistent encoding, representation and handling of text expressed in most of the world's writing systems...

 encoded as UTF-8
UTF-8
UTF-8 is a multibyte character encoding for Unicode. Like UTF-16 and UTF-32, UTF-8 can represent every character in the Unicode character set. Unlike them, it is backward-compatible with ASCII and avoids the complications of endianness and byte order marks...

. MARC-8 is based on ISO 2022 and allows the use of Hebrew, Cyrillic, Arabic, Greek, and East Asian scripts. MARC 21 in UTF-8 format allows all the languages supported by Unicode.

MARC formats

MARC formats
Name Description
Authority records provide information about individual names, subjects, and uniform title
Uniform title
A uniform title in library cataloging is a title assigned to a work which either has no title or has appeared under more than one title. It is part of authority control...

s. An authority record establishes an authorized form of each heading, with references as appropriate from other forms of the heading.
Bibliographic records describe the intellectual and physical characteristics of bibliographic resources (books, sound recordings, video recordings, and so forth).
Classification records MARC records containing classification data. For example, the Library of Congress Classification has been encoded using the MARC 21 Classification format.
Community Information records MARC records describing a service providing agency. For example, the local homeless shelter
Homeless shelter
Homeless shelters are temporary residences for homeless people which seek to protect vulnerable populations from the often devastating effects of homelessness while simultaneously reducing the environmental impact on the community...

 or tax assistance provider.
Holdings records provide copy-specific information on a library resource (call number, shelf location, volumes held, and so forth).

MARC 21


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MARC 21 is a result of the combination of the United States and Canadian MARC formats (USMARC and CAN/MARC). MARC21 is based on the ANSI
American National Standards Institute
The American National Standards Institute is a private non-profit organization that oversees the development of voluntary consensus standards for products, services, processes, systems, and personnel in the United States. The organization also coordinates U.S. standards with international...

 standard Z39.2, which allows users of different software products to communicate with each other and to exchange data. MARC 21 was designed to redefine the original MARC record format for the 21st century and to make it more accessible to the international community. MARC 21 has formats for the following five types of data: Bibliographic Format, Authority Format, Holdings Format, Community Format, and Classification Data Format. Currently MARC 21 has been implemented successfully by The British Library, the European Institutions and the major library institutions in the United States, and Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

.

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MARC 21 allows the use of two character sets, either MARC-8
MARC-8
The MARC-8 charset is a MARC standard used in MARC-21 library records. The MARC formats are standards for the representation and communication of bibliographic and related information in machine-readable form, and they are frequently used in library computer systems. The encoding now known as...

 or Unicode
Unicode
Unicode is a computing industry standard for the consistent encoding, representation and handling of text expressed in most of the world's writing systems...

 encoded as UTF-8
UTF-8
UTF-8 is a multibyte character encoding for Unicode. Like UTF-16 and UTF-32, UTF-8 can represent every character in the Unicode character set. Unlike them, it is backward-compatible with ASCII and avoids the complications of endianness and byte order marks...

. MARC-8 is based on ISO 2022 and allows the use of Hebrew, Cyrillic, Arabic, Greek, and East Asian scripts. MARC 21 in UTF-8 format allows all the languages supported by Unicode.

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MARCXML


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MARC XML is an XML
XML
Extensible Markup Language is a set of rules for encoding documents in machine-readable form. It is defined in the XML 1.0 Specification produced by the W3C, and several other related specifications, all gratis open standards....

 schema
XML schema
An XML schema is a description of a type of XML document, typically expressed in terms of constraints on the structure and content of documents of that type, above and beyond the basic syntactical constraints imposed by XML itself...

 based on the fairly common MARC21 standards.

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MARCXML was developed by the US Library of Congress
Library of Congress
The Library of Congress is the research library of the United States Congress, de facto national library of the United States, and the oldest federal cultural institution in the United States. Located in three buildings in Washington, D.C., it is the largest library in the world by shelf space and...

 and adopted by it and others as a means of easy sharing of, and networked access to, bibliographic information.

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Being easy to parse by various systems allows it to be used as an aggregation format, as it is in software packages such as MetaLib
MetaLib
MetaLib is a federated search system developed by Ex Libris Ltd. MetaLib conducts simultaneous searches in multiple, and often heterogeneous, information resources such as library catalogs, journal articles, newspapers and selected quality Internet resources. The resources are often subscription...

, though that package merges it into a wider DTD
Document Type Definition
Document Type Definition is a set of markup declarations that define a document type for SGML-family markup languages...

 specification.

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The MARC XML primary design goals included:
  • Simplicity of the schema

  • Flexibility and extensiblity

  • Lossless and reversible conversion from MARC

  • Data presentation through XML stylesheets

  • MARC records updates and data conversions through XML transformations

  • Existence of validation tools

Future

The future of the MARC formats is a matter of some debate among libraries. On the one hand, the storage formats are quite complex and are based on outdated technology. On the other, there is no alternative bibliographic format with an equivalent degree of granularity. The billions of MARC records in tens of thousands of individual libraries (including over 50,000,000 belonging to the OCLC consortium alone), creates inertia.

See also

  • Cataloging
    Cataloging
    Cataloging is the process of listing or include something in a catalog. In library science is is the producing of bibliographical descriptions of books or other kinds of documents...

  • Metadata
    Metadata
    The term metadata is an ambiguous term which is used for two fundamentally different concepts . Although the expression "data about data" is often used, it does not apply to both in the same way. Structural metadata, the design and specification of data structures, cannot be about data, because at...

  • Metadata standards
    Metadata standards
    Metadata standards are requirements which are intended to establish a common understanding of the meaning or semantics of the data, to ensure correct and proper use and interpretation of the data by its owners and users...

  • MARC-8
    MARC-8
    The MARC-8 charset is a MARC standard used in MARC-21 library records. The MARC formats are standards for the representation and communication of bibliographic and related information in machine-readable form, and they are frequently used in library computer systems. The encoding now known as...

     an encoding system
    Character encoding
    A character encoding system consists of a code that pairs each character from a given repertoire with something else, such as a sequence of natural numbers, octets or electrical pulses, in order to facilitate the transmission of data through telecommunication networks or storage of text in...

     predating Unicode
    Unicode
    Unicode is a computing industry standard for the consistent encoding, representation and handling of text expressed in most of the world's writing systems...

    . A MARC record may be in either MARC-8 or UTF-8
    UTF-8
    UTF-8 is a multibyte character encoding for Unicode. Like UTF-16 and UTF-32, UTF-8 can represent every character in the Unicode character set. Unlike them, it is backward-compatible with ASCII and avoids the complications of endianness and byte order marks...

    , as indicated by the encoding marker. See the Library of Congress's
    Library of Congress
    The Library of Congress is the research library of the United States Congress, de facto national library of the United States, and the oldest federal cultural institution in the United States. Located in three buildings in Washington, D.C., it is the largest library in the world by shelf space and...

     explanation CHARACTER SETS AND ENCODING OPTIONS: Part 2 MARC-8 Encoding Environment.
  • International Standard Bibliographic Description
    International Standard Bibliographic Description
    The International Standard Bibliographic Description is a set of rules produced by the International Federation of Library Associations and Institutions to describe a wide range of library materials within the context of a catalog. The consolidated edition of the ISBD was published in 2007...

  • Z39.50
    Z39.50
    Z39.50 is a client–server protocol for searching and retrieving information from remote computer databases. It is covered by ANSI/NISO standard Z39.50, and ISO standard 23950. The standard's maintenance agency is the Library of Congress....

  • ISO 2709
    ISO 2709
    ISO 2709 is an ISO standard for bibliographic descriptions, titled Information and documentation—Format for information exchange.It is maintained by the Technical Committee for Information and Documentation .-History:...

  • AACR2
    AACR2
    AACR2 stands for the Anglo-American Cataloguing Rules, Second Edition. It is published jointly by the American Library Association, the Canadian Library Association, and the Chartered Institute of Library and Information Professionals in the UK. The editor is Michael Gorman, a British-born...

  • LCSH
  • Henriette Avram
    Henriette Avram
    Henriette Davidson Avram was a computer programmer and systems analyst who developed the MARC format , which is the national and international data standard for bibliographic and holdings information in libraries...


External links



The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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