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 (TC 46).

History

A format for the exchange of bibliographic information, it was developed in the 1960s under the direction of 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...

 of 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...

 to encode the information printed on library cards. It was first created as ANSI

Ansi

Ansi is a village in Kaarma Parish, Saare County, on the island of Saaremaa, Estonia....

 Standard Z39.2, one of the first standards for information technology, and called Information Interchange Format. The 1981 version of the standard was titled Documentation—Format for bibliographic information interchange on magnetic tape. The latest edition of that standard is Z39.2-1994 (ISSN: 1041-5653). The ISO standard supersedes Z39.2. As of December 2008 the current standard is ISO 2709:2008.

Basic structure

A ISO 2709 record has three sections:

• Record label—the first 24 characters of the record. This is the only portion of the record that is fixed in length. The record label includes the record length and the base address of the data contained in the record. It also has data elements that indicate how many characters are used for indicators and subfield identifiers. (See Variable fields, below)
• Directory—the directory provides the entry positions to the fields in the record, along with the field tags. A directory entry has four parts and cannot exceed nine characters in length:
  • Field tag (3 characters)
  • Length of the field
  • Starting character position of the field
  • (Optional) Implementation-defined part
• Datafields (Variable fields)—a string containing all field and subfield data in the record
• Record separator—a single character (IS₃ of ISO 646
  ISO/IEC 646
  ISO/IEC 646:1991, Information technology — ISO 7-bit coded character set for information interchange, is an ISO standard that since its first edition in 1972 has specified a 7-bit character code from which several national standards are derived...
  
  )

Note that although tags are often displayed as labels on bibliographic fields and each bibliographic field has an associated tag, the tags are stored in the directory not in the bibliographic field.

Fields

There are three kinds of fields in the ISO 2709 record:

• Record identifier field—identifying the record and assigned by the organization that creates the record. The record identifier field has tag 001.
• Reserved fields—Reserved fields supply data which may be required for the processing of the record. Reserved fields always have a tag in the range 002–009 and 00A–ZZZ.
• Bibliographic Fields—these are in the range 010–999 and 0AA–ZZZ. The bibliographic fields contain data and a field separator (IS₂ of ISO 646). They can also have these optional sub-parts:
  • Indicator (0–9 characters, as coded in the Leader)—Indicators generally provide further information about the contents of the field, the relationship between the field and other fields in the record, or about action required in certain data manipulation processes (including display labels).
  • Identifier (0–9 characters)—This identifies data within the bibliographic field. Where used, identifiers are composed of a delimiter (1 char, IS₁ of ISO 646) and an identifying code (1–9 chars, as defined in the leader), plus a variable length string containing the data.

Example

MARC21 library cataloging record coded in ISO 2709 format. MARC21 is an instance of ISO 2709 that has the following characteristics:

• tags are in the range 002–999 only
• there is a two-character indicator on each field, and each character is a separately defined data element
• the identifier within data fields (called "subfield code" in MARC21) is a single ASCII character preceded by IS₁ of ISO 646.

See also

• MARC—a standard for coding library cataloging data using ISO 2709.

External links

• ISO 2709:2008 - Information and documentation -- Format for information exchange
• MARC21 specifications