ISO 25577:2013

INTERNATIONAL ISO
STANDARD 25577
Second edition
2013-12-15
Information and documentation —
MarcXchange
Information et documentation — MarcXchange
Reference number
©
ISO 2013
© ISO 2013
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior
written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of
the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2013 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 XML schema exchange of MARC records . 3
4.1 General . 3
4.2 Structure of XML schema . 4
Annex A (informative) The generic MarcXchange schema . 6
Annex B (informative) Examples . 9
Annex C (informative) Applications of the generic MarcXchange schema .17
Bibliography .18
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical Barriers
to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/TC 46, Information and Documentation, Subcommittee
SC 4, Technical interoperability.
This second edition cancels and replaces the first edition. Yet valid first edition records will be compliant
with this second edition of the standard.
iv © ISO 2013 – All rights reserved

Introduction
In 2001, the US Library of Congress developed a framework for working with MARC data in an XML
environment. The core of the framework is a MARCXML schema that allows lossless round-trip
conversion of an ISO 2709 MARC 21 record and an XML-encoded MARC 21 record.
MARCXML is tightly coupled to ISO 2709. It was obvious to generalize this to an XML-based alternative
for ISO 2709 such that any existing format based on ISO 2709 could be represented.
This International Standard describes a schema which is a generalized version of, and with as few
changes as possible to, MARCXML but which retains the original MARCXML structure. The resulting
schema is an XML extension to ISO 2709. Thus, the original elements of MARCXML are reused and
verbal links to the terminology of ISO 2709 have been added. MarcXchange is useable as a framework
for conversion of all records using the ISO 2709 syntax into XML. Extensions to MarcXchange might be
required to retain the definition and application of fields, subfields, and control characters employed in
data representation techniques specific to implementations of ISO 2709. The international exchange of
records uses local variations of internationally recognized formats as much as it uses internationally
recognized formats in the precise way in which they are prescribed for international exchange.
MarcXchange, as an internationally recognized format, is mainly intended as a framework for making
local schemas, or to which local extensions can be added. Experience has shown that there is a need for
local deviations – even if MARC 21 or UNIMARC is chosen as the local format. This schema provides a
specification for the development of local specific schemas, ensuring compatibility.
The relationship of the schema described in this International Standard to MARC and ISO 2709 are as
follows.
— The XML schema is constructed to contain MARC data.
— The schema can be used for the exchange of MARC records or to act as a “bus” to enable MARC data
records to go through further transformations such as to Dublin Core and/or processes such as
validation.
The basic components of ISO 2709 are treated in the following way in the XML schema.
— The record label is treated as a simple string.
— The directory has no counterpart in the schema; when converting from MarcXchange to ISO 2709
the directory has to be recalculated.
— The record identifier field and the control fields are treated as elements with the tag as an attribute.
— Data fields are treated as elements with the tag and indicators as attributes.
— Subfields are treated as sub-elements with the subfield code as an attribute.
INTERNATIONAL STANDARD ISO 25577:2013(E)
Information and documentation — MarcXchange
1 Scope
This International Standard specifies the requirements for a generalized XML-based exchange format
for bibliographic records as well as other types of metadata.
It does not define the length or the content of individual records and does not assign any meaning to
tags, indicators, or identifiers, these specifications being the functions of an implementation format.
This International Standard describes a generalized structure, a framework designed primarily for
communication between data processing systems, but can also be relevant for use as a processing
format within systems.
MarcXchange could potentially be used as follows:
— for representing a complete MARC record or a set of MARC records in XML;
— for original resource description in XML syntax;
— as an extension schema to METS (Metadata Encoding and Transmission Standard);
— for exchange of MARC records in XML;
— for transfer of MARC records in web services like SRU (search/retrieval via URL);
— for publisher transmission of data;
— as a temporary format in all kinds of data transformation or manipulation, e.g. conversion,
publication, editing, validation;
— for metadata in XML that can be packaged with an electronic resource.
Validation of MARC records content is not enforced by the schema but by dedicated software tailored for
the specific usage (e.g. the specific MARC-format).
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 2709, Information and documentation — Format for information exchange
ISO/IEC 646, Information technology — ISO 7-bit coded character set for information interchange
ISO/IEC 10646, Information technology — Universal Coded Character Set (UCS)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
MAchine-Readable Cataloguing
MARC
family of format standards for the storage and exchange of bibliographic records and related information
in machine-readable form
Note 1 to entry: All MARC standards conform to ISO 2709.
3.2
collection
set of records
Note 1 to entry: In the schema, this is represented by a root element named “collection”.
Note 2 to entry: The terms root element, element and attribute are in line with the definitions in XML. The term
sub-element is used for an element which is the content (or child) of another element (the parent).
3.3
record
collection of fields, including record label, directory and data
Note 1 to entry: In the schema, this is represented by a root element named “record”. It can occur alone or as a
sub-element of the “collection” element.
3.4
format
specification of the information content of record label, control fields, data fields, indicators and subfields
of an ISO 2709 record
Note 1 to entry: In the schema, an attribute, named “format”, of the “record” element is used to specify the MARC
format used in the particular record.
3.5
type
sub-application of format
Note 1 to entry: In the schema, an attribute, named “type”, of the “record” element is used to specify the application.
EXAMPLE Bibliographic record, holdings record.
3.6
record label
field occurring in an ISO 2709 record
Note 1 to entry: In the schema, this is represented by a sub-element, named “leader”, of the “record” element.
3.7
directory
index used in ISO 2709 records
3.8
control field
record identifier field or reference field in ISO 2709
Note 1 to entry: In the schema, this is represented by a sub-element, named “controlfield”, of the “record” element.
3.9
data field
type of field in ISO 2709
Note 1 to entry: In the schema, this is represented by a sub-element, named “datafield”, of the “record” element.
2 © ISO 2013 – All rights reserved

3.10
tag
three characters associated to a control field or a data field in ISO 2709 and used to identify it
Note 1 to entry: In the schema represented by an attribute, named “tag”, of the “controlfield” element and the
“datafield” element.
3.11
indicator
data element in a data field in ISO 2709
Note 1 to entry: In the schema, this is represented by attributes, named “ind1”, …, “ind9”, of the “datafield” element.
3.12
subfield
part of a data field in ISO 2709
Note 1 to entry: In the schema, this is represented by a sub-element, named “subfield”, of the “datafield” element
3.13
subfield identifier
data element consisting of a control code followed by from zero to eight characters identifying a subfield
in an ISO 2709 record
Note 1 to entry: In the schema, the subfield identifier characters following (the control code) is represented by an
attribute, named “code”, of the “subfield” element.
4 XML schema exchange of MARC records
4.1 General
The generic schema is listed in Annex A. Examples of formatted records are listed in Annex B. References
to applications of the schema are listed in Annex C.
The MarcXchange schema supports XML markup of MARC records using terminology and element
names consistent with ISO 2709.
Though ISO 2709 does not address the notion of embedded fields, it is possible to define a hierarchical
structure based on subfields. To reflect this, MarcXchange can embed fields as well as whole records,
leaving it to the specific MARC-format to decide how to make use of this facility.
ISO 2709 defines the general structure illustrated in Figure 1.
Figure 1 — ISO 2709 general structure
An ISO 2709 record contains the following components:
a) a record label (fixed length);
b) a directory (variable length);
c) a record identifier field (variable length);
d) a number of reference fields (variable length);
e) a number of data fields (variable length);
f) a field separator, i.e. separator IS2 conforming to ISO/IEC 646, which terminates the directory and
each field;
g) a record separator, i.e. separator IS3 conforming to ISO/IEC 646, which terminates eac
...

INTERNATIONAL ISO
STANDARD 25577
Second edition
2013-12-15
Information and documentation —
MarcXchange
Information et documentation — MarcXchange
Reference number
©
ISO 2013
© ISO 2013
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior
written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of
the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2013 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 XML schema exchange of MARC records . 3
4.1 General . 3
4.2 Structure of XML schema . 4
Annex A (informative) The generic MarcXchange schema . 6
Annex B (informative) Examples . 9
Annex C (informative) Applications of the generic MarcXchange schema .17
Bibliography .18
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical Barriers
to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/TC 46, Information and Documentation, Subcommittee
SC 4, Technical interoperability.
This second edition cancels and replaces the first edition. Yet valid first edition records will be compliant
with this second edition of the standard.
iv © ISO 2013 – All rights reserved

Introduction
In 2001, the US Library of Congress developed a framework for working with MARC data in an XML
environment. The core of the framework is a MARCXML schema that allows lossless round-trip
conversion of an ISO 2709 MARC 21 record and an XML-encoded MARC 21 record.
MARCXML is tightly coupled to ISO 2709. It was obvious to generalize this to an XML-based alternative
for ISO 2709 such that any existing format based on ISO 2709 could be represented.
This International Standard describes a schema which is a generalized version of, and with as few
changes as possible to, MARCXML but which retains the original MARCXML structure. The resulting
schema is an XML extension to ISO 2709. Thus, the original elements of MARCXML are reused and
verbal links to the terminology of ISO 2709 have been added. MarcXchange is useable as a framework
for conversion of all records using the ISO 2709 syntax into XML. Extensions to MarcXchange might be
required to retain the definition and application of fields, subfields, and control characters employed in
data representation techniques specific to implementations of ISO 2709. The international exchange of
records uses local variations of internationally recognized formats as much as it uses internationally
recognized formats in the precise way in which they are prescribed for international exchange.
MarcXchange, as an internationally recognized format, is mainly intended as a framework for making
local schemas, or to which local extensions can be added. Experience has shown that there is a need for
local deviations – even if MARC 21 or UNIMARC is chosen as the local format. This schema provides a
specification for the development of local specific schemas, ensuring compatibility.
The relationship of the schema described in this International Standard to MARC and ISO 2709 are as
follows.
— The XML schema is constructed to contain MARC data.
— The schema can be used for the exchange of MARC records or to act as a “bus” to enable MARC data
records to go through further transformations such as to Dublin Core and/or processes such as
validation.
The basic components of ISO 2709 are treated in the following way in the XML schema.
— The record label is treated as a simple string.
— The directory has no counterpart in the schema; when converting from MarcXchange to ISO 2709
the directory has to be recalculated.
— The record identifier field and the control fields are treated as elements with the tag as an attribute.
— Data fields are treated as elements with the tag and indicators as attributes.
— Subfields are treated as sub-elements with the subfield code as an attribute.
INTERNATIONAL STANDARD ISO 25577:2013(E)
Information and documentation — MarcXchange
1 Scope
This International Standard specifies the requirements for a generalized XML-based exchange format
for bibliographic records as well as other types of metadata.
It does not define the length or the content of individual records and does not assign any meaning to
tags, indicators, or identifiers, these specifications being the functions of an implementation format.
This International Standard describes a generalized structure, a framework designed primarily for
communication between data processing systems, but can also be relevant for use as a processing
format within systems.
MarcXchange could potentially be used as follows:
— for representing a complete MARC record or a set of MARC records in XML;
— for original resource description in XML syntax;
— as an extension schema to METS (Metadata Encoding and Transmission Standard);
— for exchange of MARC records in XML;
— for transfer of MARC records in web services like SRU (search/retrieval via URL);
— for publisher transmission of data;
— as a temporary format in all kinds of data transformation or manipulation, e.g. conversion,
publication, editing, validation;
— for metadata in XML that can be packaged with an electronic resource.
Validation of MARC records content is not enforced by the schema but by dedicated software tailored for
the specific usage (e.g. the specific MARC-format).
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 2709, Information and documentation — Format for information exchange
ISO/IEC 646, Information technology — ISO 7-bit coded character set for information interchange
ISO/IEC 10646, Information technology — Universal Coded Character Set (UCS)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
MAchine-Readable Cataloguing
MARC
family of format standards for the storage and exchange of bibliographic records and related information
in machine-readable form
Note 1 to entry: All MARC standards conform to ISO 2709.
3.2
collection
set of records
Note 1 to entry: In the schema, this is represented by a root element named “collection”.
Note 2 to entry: The terms root element, element and attribute are in line with the definitions in XML. The term
sub-element is used for an element which is the content (or child) of another element (the parent).
3.3
record
collection of fields, including record label, directory and data
Note 1 to entry: In the schema, this is represented by a root element named “record”. It can occur alone or as a
sub-element of the “collection” element.
3.4
format
specification of the information content of record label, control fields, data fields, indicators and subfields
of an ISO 2709 record
Note 1 to entry: In the schema, an attribute, named “format”, of the “record” element is used to specify the MARC
format used in the particular record.
3.5
type
sub-application of format
Note 1 to entry: In the schema, an attribute, named “type”, of the “record” element is used to specify the application.
EXAMPLE Bibliographic record, holdings record.
3.6
record label
field occurring in an ISO 2709 record
Note 1 to entry: In the schema, this is represented by a sub-element, named “leader”, of the “record” element.
3.7
directory
index used in ISO 2709 records
3.8
control field
record identifier field or reference field in ISO 2709
Note 1 to entry: In the schema, this is represented by a sub-element, named “controlfield”, of the “record” element.
3.9
data field
type of field in ISO 2709
Note 1 to entry: In the schema, this is represented by a sub-element, named “datafield”, of the “record” element.
2 © ISO 2013 – All rights reserved

3.10
tag
three characters associated to a control field or a data field in ISO 2709 and used to identify it
Note 1 to entry: In the schema represented by an attribute, named “tag”, of the “controlfield” element and the
“datafield” element.
3.11
indicator
data element in a data field in ISO 2709
Note 1 to entry: In the schema, this is represented by attributes, named “ind1”, …, “ind9”, of the “datafield” element.
3.12
subfield
part of a data field in ISO 2709
Note 1 to entry: In the schema, this is represented by a sub-element, named “subfield”, of the “datafield” element
3.13
subfield identifier
data element consisting of a control code followed by from zero to eight characters identifying a subfield
in an ISO 2709 record
Note 1 to entry: In the schema, the subfield identifier characters following (the control code) is represented by an
attribute, named “code”, of the “subfield” element.
4 XML schema exchange of MARC records
4.1 General
The generic schema is listed in Annex A. Examples of formatted records are listed in Annex B. References
to applications of the schema are listed in Annex C.
The MarcXchange schema supports XML markup of MARC records using terminology and element
names consistent with ISO 2709.
Though ISO 2709 does not address the notion of embedded fields, it is possible to define a hierarchical
structure based on subfields. To reflect this, MarcXchange can embed fields as well as whole records,
leaving it to the specific MARC-format to decide how to make use of this facility.
ISO 2709 defines the general structure illustrated in Figure 1.
Figure 1 — ISO 2709 general structure
An ISO 2709 record contains the following components:
a) a record label (fixed length);
b) a directory (variable length);
c) a record identifier field (variable length);
d) a number of reference fields (variable length);
e) a number of data fields (variable length);
f) a field separator, i.e. separator IS2 conforming to ISO/IEC 646, which terminates the directory and
each field;
g) a record separator, i.e. separator IS3 conforming to ISO/IEC 646, which terminates eac
...