Overview
ISO 25577:2013 - MarcXchange specifies a generalized XML-based exchange format for bibliographic records and other metadata. MarcXchange is an international XML schema designed to represent MARC-format data (e.g., MARC21, UNIMARC) in XML for system-to-system communication or internal processing. It generalizes MARCXML while aligning terminology and structure with ISO 2709 (the ISO format for MARC records).
Key topics and technical requirements
- Generalized XML schema: Defines a framework of elements-collection, record, leader, controlfield, datafield, subfield, and embeddeddata-to encode MARC-style records in XML.
- MARC/ISO 2709 mapping:
- leader represents the ISO 2709 record label (stored as a string).
- controlfield corresponds to record identifier/reference fields; uses a required tag attribute.
- datafield represents data fields; uses tag and optional indicator attributes (ind1 … ind9).
- subfield uses a required code attribute for subfield identifiers.
- No directory element: The ISO 2709 directory has no XML counterpart; directories must be recalculated when converting back to ISO 2709.
- Record-specific attributes: format (e.g., MARC21, UNIMARC) and type (bibliographic, authority, holdings) are available on the record and embeddeddata elements.
- Embedded data support: MarcXchange can embed fields or whole records to represent hierarchical structures.
- Character and code constraints: Subfield codes are drawn from ISO/IEC 10646 BMP row 00 (Basic Latin and Latin-1 Supplement). The schema does not support ISO 2709’s special mode with identifier length = 0 (i.e., data fields without subfields).
- Validation: The schema provides structural rules but does not enforce content-level validation of MARC field semantics-content validation is left to implementation-specific tools.
Applications
- Exchange of MARC records in XML for interoperability between library systems and metadata services
- Conversion and transformation pipelines (e.g., MARC → MarcXchange → Dublin Core)
- Packaging metadata with electronic resources and embedding MARC data in METS extensions
- Web services and transfer protocols (e.g., SRU/search-retrieval use cases)
- Temporary processing format for editing, validation, publication, or publisher data transmission
Who should use it
- Libraries, archives, and national bibliographic agencies
- Metadata specialists and cataloguers working with MARC data
- Developers and system integrators building library management systems, converters, or web services
- Vendors creating tools for MARC/XML interchange and metadata transformation
Related standards
Keywords: ISO 25577:2013, MarcXchange, MARCXML, ISO 2709, XML schema, bibliographic records, metadata exchange, MARC21, UNIMARC, metadata interoperability.
