ISO 2709:2008

Overview

ISO 2709:2008 - Information and documentation - Format for information exchange - defines a generalized, system-neutral exchange format for records that describe bibliographic and other information resources. It specifies a framework for communication between data-processing systems (not for internal system processing), including record structure, character encoding rules and control characters. The standard intentionally does not define the semantic content of tags, indicators or identifiers - those are left to implementation formats.

Key topics and technical requirements

• Record structure: Each record contains a fixed-length record label, a variable-length directory, optional record identifier and reference fields, data fields, and is terminated by a record separator.
• Record label: Fixed at 24 octets, providing essential processing parameters (record length, status, implementation codes, indicator length, identifier length, base address of data, and directory map).
• Directory and directory map: The directory is an index of entries-each entry contains a tag (3 octets), the field length, the starting character position, and an optional implementation-defined part. The record label defines the lengths of these directory parts.
• Fields and separators: Fields end with a field separator; the directory, record identifier, reference fields and data fields each require separators. The record ends with a record separator.
• Indicators and identifiers: Indicator and identifier lengths are defined in the record label; data fields may include indicators, identifiers (subfield markers), and payload data depending on those lengths.
• Character encoding and octet rules: Basic characters used in labels, directory, indicators and separators must come from ISO/IEC 646 or ISO/IEC 10646 (UCS) using UTF‑8 encoding; lengths and positions are specified in octets (8‑bit bytes).
• Implementation responsibility: ISO 2709 provides the structural framework; meaning of tags and control codes is assigned by an implementation standard or by agreement between interchange partners.

Applications and who uses it

ISO 2709 is widely applicable for interchange of bibliographic, archival, museum, and other descriptive records between library systems, metadata aggregators, cataloguing agencies, information service vendors, and system integrators. Use cases include:

• Exporting/importing bibliographic records between integrated library systems (ILS).
• Batch data exchange for cataloguing, interlibrary loan, and metadata synchronization.
• Standardizing record packaging for data migrations and system interoperability.

Keywords: ISO 2709, format for information exchange, bibliographic records, record label, directory, UTF-8, field separator, record separator, information exchange format.

Related standards

• ISO/IEC 646 - 7‑bit coded character set for information interchange
• ISO/IEC 6429 - Control functions for coded character sets
• ISO/IEC 10646 - Universal Multiple-Octet Coded Character Set (UCS) / UTF‑8 encoding

This standard is a technical interoperability foundation; implementers should combine ISO 2709’s structural rules with an implementation-specific profile that defines tags, indicators and semantic meaning.