ISO 20022-4:2013

INTERNATIONAL ISO
STANDARD 20022-4
First edition
2013-05-01
Financial services — Universal financial
industry message scheme —
Part 4:
XML Schema generation
Services financiers — Schéma universel de messages pour l'industrie
financière —
Partie 4: Génération de schéma XML

Reference number
©
ISO 2013
©  ISO 2013
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ii © ISO 2013 – All rights reserved

Contents Page
Foreword . iv
Introduction . vi
1  Scope . 1
2  Normative references . 1
3  Terms and definitions . 1
4  Background . 1
5  ISO 20022 transformation rules for MessageSet . 2
5.1  Preconditions . 2
5.2  Transformation constraints . 2
5.3  Namespaces . 2
5.4  Granularity of schemas . 3
5.5  XML MessageInstances . 3
5.5.1  Encoding . 3
5.5.2  Default namespace . 3
5.5.3  DOCTYPE . 3
5.5.4  SchemaLocation . 3
5.5.5  XML name abbreviation algorithm . 3
5.6  Completeness . 3
5.7  Method . 4
5.7.1  General . 4
5.7.2  Relationship between metamodel concepts and XML Schema artefacts . 4
5.7.3  ISO 20022 DataType transformation to XSD Schema . 9
Bibliography . 22

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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
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.
ISO 20022-4 was prepared by Technical Committee ISO/TC 68, Financial services.
This first edition cancels and replaces ISO/TS 20022-4:2004.
ISO 20022 consists of the following parts, under the general title Financial services — Universal financial
industry message scheme:
 Part 1: Metamodel
 Part 2: UML profile
 Part 3: Modelling
 Part 4: XML Schema generation
 Part 5: Reverse engineering
 Part 6: Message transport characteristics
 Part 7: Registration
 Part 8: ASN.1 generation
ISO 20022-1:2013, ISO 20022-2:2013, ISO 20022-3:2013, ISO 20022-4:2013, ISO 20022-5:2013,
ISO 20022-6:2013, ISO 20022-7:2013 and ISO 20022-8:2013 will be implemented by the Registration
Authority by no later than the end of May 2013, at which time support for the concepts set out within them will
be effective. Users and potential users of the ISO 20022 series are encouraged to familiarize themselves with
the 2013 editions as soon as possible, in order to understand their impact and take advantage of their content
as soon as they are implemented by the Registration Authority. For further guidance, please contact the
Registration Authority.
iv © ISO 2013 – All rights reserved

For the purposes of research on financial industry message standards, users are encouraged to
share their views on ISO 20022:2013 and their priorities for changes to future editions of the
document. Click on the link below to take part in the online survey:
http://www.surveymonkey.com/s/20022_2013

Introduction
This International Standard defines a scalable, methodical process to ensure consistent descriptions of
messages throughout the financial services industry.
The purpose of this International Standard is to describe precisely and completely the externally observable
aspects of financial services messaging in a way that can be verified independently against operational
messaging.
The trigger for the creation of this International Standard was the rapid growth in the scale and sophistication
of messaging within financial services during the 1990s using ISO 15022. The financial services industry (from
here on referred to as "the industry") created the first version of this International Standard as the successor to
ISO 15022 in response to that trigger. Since ISO 15022, the industry has broadened the scope from securities
to the entire industry for this International Standard.
This International Standard is based on open technology standards, which historically have evolved more
rapidly than the industry itself. Consequently, this International Standard adopted a model-driven approach
where the model of the industry's messaging can evolve separately from the evolution of the messaging
technology standards. The period during which this International Standard has emerged followed the
widespread adoption of the World Wide Web (the Web) for business. XML (eXtensible Mark-up Language)
emerged as the de facto standard for document representation on the Web and it became the first syntax for
ISO 20022.
The modelling process is further refined into three levels which, in addition to the messaging technology
standard, is why this International Standard is based on four levels: the Scope level, the Conceptual level, the
Logical level and the Physical level.
This four-level approach is based on the first four levels of the Zachman Framework. The remaining two levels
of the Zachman Framework are equivalent to the implementations and the operational levels, respectively.
In ISO 20022-1, the first, second and third levels are described in UML (Unified Modelling Language) because
it is widely supported and supports multiple levels of abstraction. The models created in accordance with this
International Standard are technology independent in that they do not require any particular physical
expression or implementation. Such models aim to describe all parts of the message exchange. The models
form the definition of the protocol between participants exchanging messages. This International Standard
defines a method that describes a process by which these models can be created and maintained by the
modellers.
The models and the Physical level artefacts are stored in a central repository, serviced by a Registration
Authority. This International Standard's repository is available on the World Wide Web and offers public
access for browsing.
The Repository is organized into two areas:
 A DataDictionary containing the industry model elements likely to have further or repeated use.
 A BusinessProcessCatalogue that contains models describing specific message definitions and business
processes, and physical syntax implementations.
This International Standard is organized into the following parts.
 ISO 20022-1 describes in MOF (Meta-Object Facility) the metamodel of all the models and the Repository.
vi © ISO 2013 – All rights reserved

 ISO 20022-2 covers the UML profile, a grounding of general UML into a specific subset defined for this
International Standard (to be used when UML is selected to define the models).
 ISO 20022-3 describes a modelling method to produce models for this International Standard.
 This part of ISO 20022 covers XML schema generation rules to transform a Logical level model into a
Physical level description in the syntaxes.
 ISO 20022-5 covers logical model alignment and reverse engineering of existing message syntaxes.
 ISO 20022-6 covers message transport characteristics that define the quality of service required by the
business process definitions so that they can operate successfully.
 ISO 20022-7 describes the process of managing the registration of models and physical syntax
implementations.
 ISO 20022-8 gives ASN.1 syntax generation rules to transform a Logical level model into a Physical level
description in ASN.1.
INTERNATIONAL STANDARD ISO 20022-4:2013(E)

Financial services — Universal financial industry message
scheme —
Part 4:
XML Schema generation
1 Scope
This part of ISO 20022 was prepared to complement the ISO 20022 Metamodel, as specified in ISO 20022-1,
with the XML syntax transformation rules to be applied by the ISO 20022 Registration Authority in order to
translate an ISO 20022 compliant MessageDefinition into an XML Schema for the description and validation of
XML Messages.
It specifies the transformation rules from level 3 to level 4. It is a deterministic transformation, meaning that the
resulting XML Schema is completely predictable for a given MessageDefinition. There is neither manual input
to the transformation itself nor manual adjustment to the result of the transformation.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 20022-1, Financial services — Universal financial industry message scheme — Part 1: Metamodel
RFC 5141, Available at http://www.rfc-archive.org/getrfc.php?rfc=5141
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 20022-1 apply.
4 Background
XML is a standard defined by W3C (the World Wide Web Consortium) that is used for the representation (i.e.
the syntax) of standardized ISO 20022 MessageDefinitions. XML leaves a lot of freedom for the exact way it is
used in a particular application. Therefore, merely stating that XML is used is not sufficient to guarantee
predictability; it is also necessary to explain how it will be used.
This part of ISO 20022 contains a set of XML design rules. These design rules define how a
MessageDefinition is transformed into an ISO 20022 XML Schema.
A valid XML document (referred to hereafter as ‘XML Instance’ or ‘Instance’) is any XML document that has
an associated description and that complies with the constraints expressed in that description. The associated
description in this case is derived from the MessageDefinition.
This part of ISO 20022 also describes how a MessageSet can be converted into XML Schemas by specifying
how a MessageDefinition is transformed into an XML Schema. This XML Schema will then make it possible to
use a validating XML Schema parser to automatically verify that a given XML Instance complies with the
constraints (or a subset of constraints) described in the Mes
...