ISO/IEC PRF 19583-26

Information technology — Concepts and usage of metadata — Part 26: XML for representation of ISO/IEC 11179-3:2013 content

Standard W3C XML Schema for exchanging content between ISO/IEC11179-3:2013 metadata registries

Technologies de l'information — Concepts et utilisation des métadonnées — Partie 26: Titre manque

General Information

• Status: Not Published
• ICS: 35.040.50 - Automatic identification and data capture techniques
• Technical Committee: ISO/IEC JTC 1/SC 32 - Data management and interchange
• Drafting Committee: ISO/IEC JTC 1/SC 32 - Data management and interchange
• Current Stage: 5020 - FDIS ballot initiated: 2 months. Proof sent to secretariat
• Start Date: 06-Mar-2026
• Completion Date: 07-Mar-2026

Overview

ISO/IEC PRF 19583-26 is an international standard developed by ISO/IEC JTC 1/SC 32, focusing on information technology and metadata management. This part of ISO/IEC 19583 specifies a standardized method for representing the content of ISO/IEC 11179-3:2013 metadata registries using W3C XML Schema. By defining a consistent XML schema structure, this standard ensures reliable exchange and validation of metadata registry content between organizations and systems, supporting interoperability and compliance across diverse registry implementations.

The primary goal is to facilitate the exchange of compliant metadata-particularly data elements and value domains-between ISO/IEC 11179-3:2013-compliant registries, regardless of the underlying registry software or infrastructure. This standard is essential for organizations aiming to maintain precise, consistent metadata across distributed databases, metadata registries, and information systems.

Key Topics

• W3C XML Schema Representation
  • Defines how ISO/IEC 11179-3:2013 content is mapped into XML Schema for unambiguous exchange.
  • Ensures class and attribute names match the conceptual model of the source standard.
• Conformance Levels
  • Distinguishes between strictly conforming and conforming implementations to support both maximum interoperability and flexible extensions.
  • Strictly conforming registries produce XML documents fully validating against the standard schema.
• Content Mapping Principles
  • Outlines clear mapping conventions-including naming and referencing-between ISO/IEC 11179-3 classes/attributes and XML.
  • Supports directionality and reference-based relationships for robust content structure.
• Schema Structure
  • The standard provides a modular schema structure, including:
    • Common facilities schema (base types and utilities)
    • “Four corners” schema (key content aggregates)
    • Message schema (for exchanging registry content)
• Metadata Exchange Use Cases
  • Supports detailed replication, small-scale sharing, and data-element exchange between various systems.
  • Addresses scenarios ranging from large compliant registries to local or configurable information systems.

Applications

ISO/IEC PRF 19583-26 delivers practical value for organizations involved in information management, data governance, or regulatory compliance:

• Metadata Registry Interoperability
  • Enables seamless exchange of metadata elements and value domains between registries adhering to ISO/IEC 11179-3:2013, reducing manual integration efforts.
• Consolidation of Disparate Metadata
  • Supports unifying metadata definitions in large organizations or federated systems using varying registry platforms.
• Foundation for XML Databases
  • Provides XML schema structures suitable for both message exchange and as the basis for XML-native metadata registry implementations.
• Inter-system Communication
  • Facilitates integration between registry-driven data dictionaries, survey systems, and configurable information systems with or without published conceptual models.
• Compliance and Validation
  • Ensures that exchanged metadata meets standard conformance requirements and validation rules-critical for auditability and regulatory frameworks.

Related Standards

Implementing ISO/IEC PRF 19583-26 benefits from alignment with these related standards:

• ISO/IEC 11179-3:2013
  Information technology - Metadata registries (MDR) - Part 3: Registry metamodel and basic attributes
  Defines the core conceptual model underlying this XML schema representation.

• ISO/IEC 11179-6:2015
  Information technology - Metadata registries (MDR) - Part 6: Registration
  Specifies rules for registering and administering metadata items.

• W3C XML Schema
  The underlying language used for formalizing XML document structures and ensuring data exchange compatibility.

• ISO/IEC DTR 19583-24
  Describes a Resource Description Framework Schema (RDFS) for ISO/IEC 11179-3, complementing the XML-based approach.

Adopting ISO/IEC PRF 19583-26 ensures future-ready, standards-based metadata exchange, supporting long-term data interoperability and compliance in information technology environments.

Standards Content (Sample)

DRAFT
International
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ISO/IEC
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19583-26
ISO/IEC JTC 1/SC 32
Information technology — Concepts
Secretariat: ANSI
and usage of metadata —
Voting begins on:
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XML for representation of ISO/IEC
Voting terminates on:
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11179-3:2013 content
ICS: 35.040.50
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ISO/IEC DIS 19583-26:2024(en)
DRAFT
ISO/IEC DIS 19583-26:2024(en)
International
Standard
ISO/IEC
DIS
19583-26
ISO/IEC JTC 1/SC 32
Information technology — Concepts
Secretariat: ANSI
and usage of metadata —
Voting begins on:
Part 26:
XML for representation of ISO/IEC
Voting terminates on:
11179-3:2013 content
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© ISO/IEC 2024 – All rights reserved
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ISO/IEC DIS 19583-26:2024(en)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
3.1 General computing terms .1
3.2 Terms relating to XML Schema and RDF .2
4 Conformance . 3
4.1 Overview of Conformance .3
4.2 Degree of Conformance .3
4.2.1 General .3
4.2.2 Strictly conforming implementations .3
4.2.3 Conforming implementations .3
5 Use cases, modelling principles and mapping conventions . 3
5.1 Introduction .3
5.2 Directionality and indirection of Relationships .4
5.3 Schema documents .5
5.4 Schema style .5
5.5 Schema conventions .5
6 Overview of ISO/IEC 11179-3 Representation in XML Schema . 5
6.1 Basic Types metamodel region (ISO/IEC 11179-3:2013, 6.2) .5
6.2 Basic Classes metamodel region (ISO/IEC 11179-3:2013, 6.3).6
6.3 Identification metamodel region (ISO/IEC 11179-3:2013, 7.2) .6
6.4 Designation and Definition metamodel region (ISO/IEC 11179-3:2013, Clause 7).6
6.5 Registration metamodel region (ISO/IEC 11179-3:2013, Clause 8) .6
6.6 Concepts package (ISO/IEC 11179-3:2013, Clause 9), Binary Relations package (ISO/
IEC 11179-3:2013, Clause 10) .6
6.7 Metadata Item Type .7
6.8 Data Description package (ISO/IEC 11179-3:2013, Clause 11).7
6.8.1 General .7
6.8.2 Measurement metamodel region (ISO/IEC 11179-3, 11.4) .7
6.8.3 Data Element Concept metamodel region (ISO/IEC 11179-3, 11.2) .7
6.8.4 Conceptual and Value Domain metamodel region (ISO/IEC 11179-3, 11.3) .7
6.8.5 Data_Element metamodel region (ISO/IEC 11179-3, 11.5) .8
6.9 ISO/IEC 11179-3 Message and Database Schema .8
Annex A (informative) Summary of differences between ISO/IEC 11179-3:2013 and ISO/IEC
11179-3:2023, ISO/IEC 11179-31:2023 and ISO/IEC 11179-32:2023 . 9
Annex B (Normative) Common Facilities Schema .13
Annex C (Normative) ‘Four Corners’ Schema .33
Annex D (Normative) Message Schema .42
Annex E (Normative) Example Database Schema .45
Annex F (Normative) Class, attribute and relation name correspondence . 47
Bibliography .49

© ISO/IEC 2024 – All rights reserved
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ISO/IEC DIS 19583-26:2024(en)
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 voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the World
Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following URL:
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/IEC JTC1, Information Technology, Subcommittee
SC 32, Data Management and Interchange.
A list of all parts in the ISO/IEC 11179 series can be found on the ISO website.

© ISO/IEC 2024 – All rights reserved
iv
ISO/IEC DIS 19583-26:2024(en)
Introduction
ISO/IEC 11179 addresses the semantics of data, the representation of data, and the registration of the
descriptions of that data. At the time of the publication of ISO/IEC 11179-3:2013 to which this document
refers, ISO/IEC 11179 was a six-part standard, whose conceptual model was specified in ISO/IEC 11179-3.
Since this time part three has continued to be refined, developed and factorized.
ISO/IEC 11179-3 does not define a physical implementation and thus need not be implemented as specified,
which makes exchanging content between even compliant registries difficult. A common physical
implementation is required if automatic content exchange is to be achieved.
ISO/IEC 11179-3:2013 representation in W3C XML Schema is such a physical representation. It also provides
a potential model for its implementation as an XML database focused on units of content that are readily
created and maintained – particularly if reasoning over the ‘meaning’ of that content can be delegated to an
1)
accompanying RDF database as described in ISO/IEC DTR 19583-24 .
The schema is presented in ‘Venetian Blind’ style, where each of the components of the model are rendered
as reusable types. These types are assembled into discrete documents suitable for creation and exchange.
1) Under preparation. Stage at the time of publication: ISO/IEC DTR 19583-24:2023

© ISO/IEC 2024 – All rights reserved
v
DRAFT International Standard ISO/IEC DIS 19583-26:2024(en)
Information technology — Concepts and usage of metadata —
Part 26:
XML for representation of ISO/IEC 11179-3:2013 content
1 Scope
This document specifies the structure of ISO/IEC 11179-3:2013 representation in W3C XML Schema
suitable for communication of content between compliant registries. The schema described in this
standard will implement a class and attribute vocabulary that matches the conceptual model presented
in ISO/IEC 11179-3:2013 in W3C XML Schema format. The purpose of the schema is for the exchange of
compliant metadata, and to support the validation of messages exchanged between registries. It is not
intended for the communication of data element metadata alongside the data to which the metadata refers.
The document specifes the schema and the principles and conventions that were followed to map classes,
attributes, and associations of the conceptual model into an acyclic, directed graph suitable for an
unambiguous document-based representation.
As the adoption of 11179 MDRs expands, we anticipate that metadata registries will need to reuse and
extend definitions from other MDRs, together with definitions reflecting local information types. The
schema allows metadata registry content to be exchanged in a standard format regardless of the kind of
registry software in use.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements 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/IEC 11179-3:2013, Information technology — Metadata registries (MDR) Part 3: Registry metamodel and
basic attributes
ISO/IEC 11179-6:2015, Information technology — Metadata registries (MDR) Part 6: Registration
W3C XML Schema https:// www .w3 .org/ XML/ Schema
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO/IEC 11179-3:2013,
ISO/IEC 11179-6:2015 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1 General computing terms
3.1.1
extension
feature not defined by this part of ISO/IEC 19583

© ISO/IEC 2024 – All rights reserved
ISO/IEC DIS 19583-26:2024(en)
3.1.2
knowledge organization system
generic term referring to systems and schemes used to manage and organize knowledge
3.1.3
namespace
classification scheme that permits a given name to identify multiple objects that are distinguished by context
[SOURCE: ISO/IEC 39075:2024]
3.1.4
namespace prefix
short name to uniquely identify the namespace
[SOURCE: ISO 24531:2013]
3.1.5
schema
formal definition of a model
[SOURCE: ISO 16684-2:2024]
3.2 Terms relating to XML Schema and RDF
3.2.1
Unicode
system of uniquely identifying (numbering) characters such that nearly any character in any language is
identified
[SOURCE: ISO 11002:2008]
3.2.2
Internationalized Resource Identifier
IRI
sequence of characters that conforms to the syntax defined in RFC 3987
[SOURCE: ISO/IEC 19722-7:2019]
3.2.3
World Wide Web Consortium
W3C
international community that develops open standards to ensure the long-term growth of the Web
[SOURCE: ISO 8:2019]
3.2.4
XML Schema
language for describing the structure and constraining the contents of XML documents
[SOURCE: ISO 25720:2009, 4.32]
3.2.5
resource
element from a universe of discourse denoted by an IRI (3.2.2)
3.2.6
Resource Description Framework
RDF
formal syntax and semantics for expressing descriptions of resources (3.2.5) that can be represented as a
directed data graph
© ISO/IEC 2024 – All rights reserved
ISO/IEC DIS 19583-26:2024(en)
4 Conformance
4.1 Overview of Conformance
Conformance claims shall specify a Degree of Conformance. Where the schemas are used to validate a
message, the degree of conformance shall be defined as described below. Where these schemas are used
as part of a data model for an XML implementation of a registry, conformance may additionally be claimed
against ISO/IEC 11179-3:2013. While such conformance must be established on a case-by-case basis, it is to
be expected that such a registry will be able to claim to be ‘conforming’.
4.2 Degree of Conformance
4.2.1 General
The distinction between “strictly conforming” and “conforming” implementations is necessary to address
the simultaneous needs for interoperability and extensions. This document describes specifications that
promote interoperability.
A strictly conforming implementation can be limited in usefulness but is maximally interoperable with
respect to this document. A conforming implementation can be more useful but can be less interoperable
with respect to this document.
4.2.2 Strictly conforming implementations
A strictly conforming registry shall emit XML documents that validate against the schema described
in this standard without error when using a validator that is fully conformant with the W3C XSD 1.1
Recommendation of 5 April 2013.
4.2.3 Conforming implementations
A conforming registry shall emit XML documents that use the namespace, document, element and attribute
names together with the containment hierarchy described in this standard. It need not meet the explicit
cardinality requirements of the schema; it may include extra elements and attributes in other namespaces
where extension elements are allowed. Mandatory elements and attributes may be omitted entirely, or
repeated in greater numbers than the schema allows.
5 Use cases, modelling principles and mapping conventions
5.1 Introduction
The contained schema is intended principally for the exchange of Data Element and Value Domain content
between registries and modelling environments and for the use of such content in the configuration
of information systems. It may also be used – in part or as a whole – as a foundation of a compliant XML
database implementation of ISO/IEC 11179-3:2013.
There are three broad use cases for information exchange between registries
a) Detailed replication of large amounts of content between ISO/IEC 11179-3:2013 compliant registries
whose audiences are in agreement on the conceptualisation of the data elements exchanged,
b) Smaller scale exchange of data elements between registries in partly overlapping domains that have
different conceptual models,
c) Exchange of data element content between configurable information systems or local data dictionaries
and registries that have no published conceptual models and registries in their domain.
The first use case requires a sophisticated way of exchanging a broad range of content and its
interrelationships. ISO/IEC DTR 19583-24 describes a Resource Description Framework Schema (RDFS)

© ISO/IEC 2024 – All rights reserved
ISO/IEC DIS 19583-26:2024(en)
for ISO/IEC 11179-3:2013 which is capable of faithfully representing the ISO/IEC 11179-3:2013 conceptual
model with few compromises, and this is recommended here.
For the second, while understanding the original context of data element and value domain content is
important, imported content will be relocated in the conceptual model of the target registry. An example here
is the reuse of specific data element content for the Identification of Medicinal Products (ISO 11615:2017;
ISO 11616:2017; ISO 11238:2018) in registries whose audiences run pharmacies and prescribe and
administer drugs. It is not necessarily the case that the Conceptual Domains, Object Classes, Properties and
Data Element Concepts that support such data elements for regulatory purposes translate directly to ones
that help people reuse product identification information in patient care.
For the last use case content will be partial – data element names, units of measure, datatypes, valid values
and meanings, and versioning information may be present, but rigorous notions corresponding to the upper
half of ISO/IEC 11179-3:2013 Figure 11 (i.e. data element concept and conceptual domain) will not. Examples
include survey systems – such as Google Forms, SurveyMonkey, RedCap OpenClinica – and more generally
from information systems where user-facing forms or data elements may be configured within the product
as part of its deployment.
Where the schema is intended to support the development of an XML database, the design fits in with an
overall approach where the model is factored into units that map to content creation workflows, and for each
identified item there is one (or a small number) of related content creation forms. In such an implementation,
XQuery would be used to navigate from shared leaf classes, and to hide administrative metadata from
summary views such as content maps, tree browsers, alphabetic listings and search forms. Implementers
will need to provide simple additional schemas that declare XML elements for the types they wish to offer to
the users as content creation points, or alternatively they could include these element definitions in a choice
element in a single schema.
The goal of ISO/IEC 11179-3 Representation in XML Schema is to provide a near complete and faithful mapping
of all classes, attributes, and associations of the ISO/IEC 11179-3:2013 conceptual model to a schema based
on W3C XML Schema language in a more deterministic, fixed model that can be easily deployed, focused
on creating, managing and exchanging Data Element and Value Domain content. The assumptions made in
the translation of the conceptual model into a physical representation are outlined in general below, and in
specific in the narrative in clause 6.
5.2 Directionality and indirection of Relationships
In ISO/IEC 11179-3:2013, relationship directionality and end point visibility are not specified, and there
are many points in the model where it is possible to create content that indirectly references itself either
immediately or as part of larger cyclic structures. While direct implementation of such models is possible
in XML Schema, additional code – Schematron rules or an XForm/XQuery API – is required to ensure
documents that validate against the schema make sense. To avoid this problem, the schemas specified here
assert directionality, and implement certain important relationships as references.
The default directionality can be generally stated as having Data Element, Value Domain, Data Element
Concept and Conceptual Domains as the base units of content and exchange, with reference relationships
between these classes. It is assumed that these items will be ‘identified items’ according to the definition of
ISO/IEC 11179-3:2013, and thus the reference is to the item identifier for that item. Within each of these units,
dependent content is represented as a hierarchy of nodes. An exception to this principle is made for value
meanings where a choice between referring to the meaning in a separate Conceptual Domain definition, or
including the meaning directly in the Value Domain is offered to implementers who have the third use case
in clause 5.1.
The model additionally defines many shared classifiers including Context, Object Class, Property, and Units
of Measure. To avoid duplication of this content at every point of reference in the XML document, these are
also required to be identified items. However, for the sake of brevity these classifiers are strictly leaves,
without explicit navigability back to the related classes: for example each Data Element Concept instance that
is classified by a particular Object Class instance is not enumerated in that Object Class instance. Reverse
links can be computed using XQuery inside an XML database representation. Additionally it is possible to
separately specify Organisations, Individuals and Contacts for large exchanges of content between registries.

© ISO/IEC 2024 – All rights reserved
ISO/IEC DIS 19583-26:2024(en)
5.3 Schema documents
Three schema documents are presented in Annexes A, B and C:
a) iso11179-3_common_facilities.xsd presents the types described as common facilities in
ISO/IEC 11179-3:2013. This schema document is widely applicable to standards from the 11179 and
19763 families (Annexe A).
b) iso11179-3_four_corners.xsd assembles the common facilities into the main content types of an
ISO/IEC 11179-3:2013 compliant registry (Annexe B).
c) iso11197-3_message.xsd uses the previous schema to define a document structure for exchanging
content between compliant registries (Annexe C).
5.4 Schema style
The style of the schema is to define a large number of global type definitions at various levels of complexity
and integration and to make these specific with local element definitions that tightly specify the kinds
of elements that can be used to compose documents. As such a Postal_Address type is defined without
presumption that a root element of type Postal_Address will actually appear as a stand-alone XML document,
it being left to the user as to how these types are presented as a collection of documents.
The schema is presented in three parts: a ‘common facilities’ schema containing global base type definitions
for use in all implementations; a ‘four corners’ schema that assembles these common facilities into a selection
of types most useful for the creation of content interchange messages, and an overarching ‘message’ schema
that assembles these types into an XML document that is used to exchange content.
It is expected that the underlying implementations of ISO/IEC 11179-3 that registry users will interact
with to create content will be most often relational, with XML representations used for content exchange
and RDF representations used for computation. Therefore, these schemas do not make use of specific XML
capabilities such as ID/IDREF for the reuse of content by reference, or any of the proposed mechanisms for
content inclusion such as XInclude. XML database implementers may wish to modify elements of the schemas
to utilise such features in their implementation platform.
5.5 Schema conventions
The following conventions have been used for mapping the ISO/IEC 11179-3 model elements to W3C XML Schema.
Every model element is represented in W3C XML Schema in the namespace https:// www .iso .org/ 11179/ -3/
2013 and is abbreviated with the namespace prefix iso-11179.
Every class of ISO/IEC 11179-3 is represented by a simple or complex type. Names maintain the capitalization
and underscores as specified in the parent standard.
6 Overview of ISO/IEC 11179-3 Representation in XML Schema
ISO/IEC 11179-3:2013 specifies ‘item types’ such that later classes can be typed by one or more of these
types. Each of these item types is rendered as an xsd:group since W3C XML Schema does not support
multiple inheritance. e.g. Identified_Item; Designatable_Item.
Certain relationships between classes have been replaced by reference to their scoped identifier rather than
by inclusion of content. e.g. Namespace from Scoped_Identifier, designation_context from Designation.
6.1 Basic Types metamodel region (ISO/IEC 11179-3:2013, 6.2)
Basic types defined in ISO/IEC 11179-3:2013 are declared as simple types, indirected from the corresponding
XML base datatypes. It is expected that the base datatypes will function correctly in interchange and
database use cases, but indirection allows users of the schema components to further restrict the base types
if required, such as disallowing symbols in a datatype expected to hold a filename.

© ISO/IEC 2024 – All rights reserved
ISO/IEC DIS 19583-26:2024(en)
6.2 Basic Classes metamodel region (ISO/IEC 11179-3:2013, 6.3)
Basic classes are faithfully represented from the standard.
6.3 Identification metamodel region (ISO/IEC 11179-3:2013, 7.2)
It is at this point that the model in ISO/IEC 11179-3:2013 becomes more conceptual with the implementer
invited to decide what items to identify, name and define, together with some structures that have the
potential to be recursive. This implementation has made the following assumptions:
— Namespaces are required to be identified and referenced by identifier when used. To avoid the recursive
relationship, attributes for identifier and version have been directly included in the type.
— Scoped identifiers exist as part of an identified item that refers to their namespace by reference, rather
than existing within a namespace node, as implied by a simple reading of the class diagram.
Identified_Item is rendered from the standard as a schema group for inclusion in later classes. It is assumed
in this schema that Scoped_Identifier will not exist separately of an Identified_Item.
6.4 Designation and Definition metamodel region (ISO/IEC 11179-3:2013, Clause 7)
This implementation has made the following assumptions:
— Naming Conventions are identified items, instances are referenced by their scoped identifiers.
— Context is set to be both an identified item and a designatable item. The recursive relationships to
designation and definition contexts have been removed by localising appropriate attributes from the
definition and designation classes within the Context type.
— Relationships between designations have been supported in the following way: it is possible to include
a specific definition local to a designation, and a designation may be listed as a designation_heading,
assuming that the specific definition only has context alongside its designation, and that designations
are unique.
6.5 Registration metamodel region (ISO/IEC 11179-3:2013, Clause 8)
Implementation of the registration and administration classes is mostly as described in the standard except
for the implementation of relationships between registered item, administered item and attached item.
The combination of the inheritance relationship between registered, administered and attached item and
the composition relationship between administered and attached item creates errors in later parts of the
schema if both the administered and attached item types contain registered item attributes. Implementation
of the inheritance relationship is deferred until the introduction of the ‘Metadata_Item’ type to encapsulate
the notions of identification, naming, classification, registration, administration and attachment.
6.6 Concepts package (ISO/IEC 11179-3:2013, Clause 9), Binary Relations package (ISO/IEC
11179-3:2013, Clause 10)
As modelled, the concepts and binary relations packages contain the greatest scope for recursion and
repetition of content when implementing the conceptual model as a hierarchical structure. Since it is best
practice for every concept in a concept system to be explicitly identified and named, this implementation has
taken the opportunity to replace many of the relationships between classes in this part of the model with
scoped identifier references, with attributes at both endpoints of the relationship.
It is also best practice to administer/publish a concept system as a complete entity, rather than in pieces.
Thus administration and attachment are reserved for the Concept_System type, rather than being applied to
its components.
© ISO/IEC 2024 – All rights reserved
ISO/IEC DIS 19583-26:2024(en)
6.7 Metadata Item Type
The overall approach of the modelling in ISO/IEC 11179-3 is to define a number of conceptual ‘types’ that
may be applied to content. Thus identification, classification, designation, registration, administration and
attachment all have associated types that are applied by the implementer according to the policies specified
by the registrar. This allows the standard to support a wide variety of registries from those that create and
maintain content in detail to ones that aggregate content that is registered elsewhere.
W3C XML schema does not support multiple inheritance. The approach taken has been to declare an
abstract class of ‘Metadata_Item’ – which can optionally be identified, named, classified, registered and
either administered or attached – and for the classes in the data description class to inherit from this. This
simplifies the definition of types in the data description package, and provides a basis for further work
developing schemas for other parts of ISO/IEC 11179 together with the ISO/IEC 19763 family that share
these notions.
6.8 Data Description package (ISO/IEC 11179-3:2013, Clause 11)
6.8.1 General
The approach taken to the data description package is to broadly support content kinds according to the ‘four
corners’ high level conceptual model for the data description package (ISO/IEC 11179-3:2013, Figure 11) – a
complex type is defined for each concrete class at the four corners. Implementers of XML databases may find
this causes performance issues with enumerated conceptual and value domains and wish to factorize these
classes differently.
One issue with an XML schema implementation of the data description package is in the choice of class to
inherit from. Object Class, Property, Data Element Concept, Conceptual Domain and Value Meaning are
all kinds of Concept, but unlike concepts in a concept system – which are administered as a system – they
may require individual administration. This implementation treats these objects as being distinct from
any general concept system – i.e. either designatable or metadata items – with an additional, optional
relationship to a concept in a concept system. This is semantically safest – an assertion of association from
one of these objects to a concept cannot dislocate the target concept from its proper place in the concept
system, whereas stating equivalence between – say – a value meaning and a concept introduces to the
concept system associations with the other value meanings and the containing conceptual domain that risks
changing the concept’s meaning.
6.8.2 Measurement metamodel region (ISO/IEC 11179-3, 11.4)
Since value domains measured with comparable/convertible units will usually fall naturally into the same
conceptual domain, a registry may simply maintain a flat list of units of measure and exchange these as
required when they exchange value domains. If more order is desired, since conceptually different units
of measure may share the same dimension (e.g. frequency, angular velocity), Measure_Class is the natural
containing class of this region, the compromise being that this prevents units of measure belonging to more
than one measure class.
6.8.3 Data Element Concept metamodel region (ISO/IEC 11179-3, 11.2)
Data element concepts, object classes and properties are all set to be kinds of Metadata_Item, with an
additional concept reference to represent the assertion of association/equivalence with a concept in a
registered concept system.
6.8.4 Conceptual and Value Domain metamodel region (ISO/IEC 11179-3, 11.3)
Conceptual and Value Domains are set to be kinds of Metadata_Item, with an additional concept reference
to represent the assertion of association/equivalence with a concept in a registered concept system. Value
Meanings include groups for identification and designation, and additionally also have a concept reference.
It is assumed that the set of Value Meanings are part of the Conceptual Domain and thus share their
administration record, the same assumption applies to Permissible Values and Value Domains. However, the
option is available to exchange meanings within a Value Domain where Conceptual Domains are unavailable.

© ISO/IEC 2024 – All rights reserved
ISO/IEC DIS 19583-26:2024(en)
6.8.5 Data_Element metamodel region (ISO/IEC 11179-3, 11.5)
Data Elements, their derivations, and derivation rules themselves each are set to be Metadata Items with
their own administration records.
6.9 ISO/IEC 11179-3 Message and Database Schema
Finally, the types defined above are brought together into a ‘metadata bundle’, a simple sequence of nodes
of the main content kinds in an ISO/IEC 11179-3:2013 registry, together with the registry specification and
the date and time of export (Annex C). An example database schema is also offered in Annex D, although it
is anticipated that the basic components of ISO/IEC 11179-3:2013, and the schema elements suggested here,
could be brought together in many different ways.

© ISO/IEC 2024 – All rights reserved
ISO/IEC DIS 19583-26:2024(en)
Annex A
(informative)
Summary of differences between ISO/IEC 11179-3:2013
and ISO/IEC 11179-3:2023, ISO/IEC 11179-31:2023 and
ISO/IEC 11179-32:2023
A.1 Overview
This document is targeted at ISO/IEC 11179-3:2013, but that document has been superseded
by ISO/IEC 11179-3:2023 and other parts of ISO/IEC 11179, such as ISO/IEC 11179-31:2023 and
ISO/IEC 11179-32:2023. This Annex provides an overview of the differences.
A.2 Modularization of ISO/IEC 11179-3:2013
In the 2023 edition, ISO/IEC 11179-3:2013 has been split into multiple parts to make it more manageable.
The following are the new parts:
— ISO/IEC 11179-30 Basic attributes of metadata;
— ISO/IEC 11179-31 Metamodel for data specification registration;
— ISO/IEC 11179-32 Metamodel for concept system registration.
A.3 Simplification of the UML metamodel
Some changes were made in the 2023 edition to simplify the UML model:
— elimination of the use of UML stereotypes;
— addition of an explicit 'Item' class as the superclass of all types of registry items;
— removal of role names on associations;
— removal of redundant specification of attributes and associations in the text.
A.4 Refactoring of some of the packages to reduce dependencies
Some changes were made in the 2023 edition to reduce dependencies among packages:
— moving the Concept class to the Basic and Core package where it is referenced from multiple metamodel
regions, including: the Data Specification package in ISO/IEC 11179-31, the Concept System package in
ISO/IEC 11179-32, the Data Set package in ISO/IEC 11179-33 and the Model package in ISO/IEC 11179-35;
— moving the Context class to the Basic and Core package where it is referenced from the Designation and
Definition package in ISO/IEC 11179-3:2023, the Data Specification package in ISO/IEC 11179-31 and the
Data Set package in ISO/IEC 11179-33;
— moving the Slot class to the Basic and Core package, a more appropriate location than the Identification
package;
— restoring a Classification region, based on the style of ISO/IEC 11179-3:2003, to remove dependency on
the Concept System region for classification.

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A.5 Use of UML stereotypes in ISO/IEC 11179-3:2013
UML stereotypes were used in ISO/IEC 11179-3:2013. Each of these types (except Registered_Item which is
abstract and cannot be instantiated) can be applied to any of the instances of metadata items in the registry.
In ISO/IEC 11179-3:2023, the use of stereotypes has been replaced by subclassing from the superclass Item,
which is specified in the new Core metamodel region and which did not exist in the 2013 edition.
A.6 Differences in the Identification metamodel region
In the 2013 edition, Identified_Item is a <> which needs to be applied to instances of metadata items
that are to be identified. In the 2023 edition, Identified_Item is a regular class related to Item by the item_
identification association.
Also, Slot in the 2013 edition is related to Identified_Item, whereas in the 2023 edition it is related to Item
in the Core metamodel region.
A.7 Differences in the Designation and Definition metamodel region
In the 2013 edition, Designatable_Item is <> which needs to be applied to instances of metadata
items that are to be designated or defined;
In the 2023 edition, Designatable_Item is replaced by Item, which can be directly related to the Designation
and Definition classes;
In the 2013 edition, designation_definition_pairing is a simple association between Designation and
Definition. In the 2023 edition, Designation_Definition_Pairing is an association class, which is also
associated with Context, and has an attribute acceptability.
A.8 Differences in the Registration metamodel region
In the 2013 edition, Administered_Item and Attached_Item are <> which need to be applied to
instances of metadata items that are to be administered or attached. In the 2023 edition, Administered_
Item and Attached_Item are regular classes which are associated with Item through the item_identification
association of the grandparent class Identified_Item;
In the 2013 edition, Registration is an association class, with a registration_state attribute, and an
Administered_Item can be associated with multiple Registration_Authorities;
In the 2023 edition, registration is a simple association with a single Registration_Authority and
registration_state has been moved to Administered_Item.
In the 2023 edition, there are several differences in the Registry_Specification class:
— the attributes standard and conformance_level have been made optional;
— the attribute primary_language has been renamed default_language and zero, one or more alternative_
languages can be specified;
— reference_document_identifier_form has been renamed reference_document_identifier_kind;
— representation_class_scheme has been replaced by representation_class_scheme_id, so that only the
identifier of the concept system is stored, rather than the concept system itself;
— Several new attributes have been added:
— degree_of_conformance;
— conformance_label;
© ISO/IEC 2024 – All rights reserved
ISO/IEC DIS 19583-26:2024(en)
— included_features;
— excluded_features.
A.9 Differences in the Concepts metamodel region
The differences are minor. T
...

International
Standard
ISO/IEC 19583-26
First edition
Information technology — Concepts
and usage of metadata —
Part 26:
XML for representation of ISO/IEC
11179-3:2013 content
PROOF/ÉPREUVE
Reference number
ISO/IEC 19583-26:2026(en) © ISO/IEC 2026

ISO/IEC 19583-26:2026(en)
© ISO/IEC 2026
All rights reserved. Unless otherwise specified, or required in the context of its implementation, 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
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
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ISO/IEC 19583-26:2026(en)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
3.1 General computing terms .1
3.2 Terms relating to XML Schema and RDF .2
4 Conformance . 2
4.1 Overview of conformance . .2
4.2 Degree of conformance .3
4.2.1 General .3
4.2.2 Strictly conforming implementations .3
4.2.3 Conforming implementations .3
5 Use cases, modelling principles and mapping conventions . 3
5.1 General .3
5.2 Directionality and indirection of relationships .4
5.3 Schema documents .4
5.4 Schema style .5
5.5 Schema conventions .5
6 Overview of ISO/IEC 11179-3:2013 Representation in XML Schema . 5
6.1 General .5
6.2 Basic Types metamodel region (ISO/IEC 11179-3:2013, 6.2) .6
6.3 Basic Classes metamodel region (ISO/IEC 11179-3:2013, 6.3).6
6.4 Identification metamodel region (ISO/IEC 11179-3:2013, 7.2) .6
6.5 Designation and Definition metamodel region (ISO/IEC 11179-3:2013, Clause 7).6
6.6 Registration metamodel region (ISO/IEC 11179-3:2013, Clause 8) .6
6.7 Concepts package (ISO/IEC 11179-3:2013, Clause 9), Binary Relations package (ISO/
IEC 11179-3:2013, Clause 10) .6
6.8 Metadata Item Type .7
6.9 Data Description package (ISO/IEC 11179-3:2013, Clause 11).7
6.9.1 General .7
6.9.2 Measurement metamodel region (ISO/IEC 11179-3:2013, 11.4) .7
6.9.3 Data Element Concept metamodel region (ISO/IEC 11179-3:2013, 11.2).7
6.9.4 Conceptual and Value Domain metamodel region (ISO/IEC 11179-3:2013, 11.3) .8
6.9.5 Data_Element metamodel region (ISO/IEC 11179-3:2013, 11.5) .8
6.10 ISO/IEC 11179-3:2013 Message and Database Schema .8
Annex A (informative) Summary of differences between ISO/IEC 11179-3:2013 and ISO/IEC
11179-3:2023, ISO/IEC 11179-31:2023 and ISO/IEC 11179-32:2023 . 9
Annex B (normative) Common Facilities Schema .13
Annex C (normative) ‘Four Corners’ Schema .34
Annex D (normative) Message Schema .43
Annex E (informative) Example Database Schema .46
Annex F (informative) Class, attribute and relation name correspondence .48
Bibliography .50
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Foreword
ISO (the International Organization for Standardization) and IEC (the International Electrotechnical
Commission) form the specialized system for worldwide standardization. National bodies that are
members of ISO or IEC participate in the development of International Standards through technical
committees established by the respective organization to deal with particular fields of technical activity.
ISO and IEC technical committees collaborate in fields of mutual interest. Other international organizations,
governmental and non-governmental, in liaison with ISO and IEC, also take part in the work.
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 document 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 or www.iec.ch/members_experts/refdocs).
ISO and IEC draw attention to the possibility that the implementation of this document may involve the
use of (a) patent(s). ISO and IEC take no position concerning the evidence, validity or applicability of any
claimed patent rights in respect thereof. As of the date of publication of this document, ISO and IEC had not
received notice of (a) patent(s) which may be required to implement this document. However, implementers
are cautioned that this may not represent the latest information, which may be obtained from the patent
database available at www.iso.org/patents and https://patents.iec.ch. ISO and IEC shall not be held
responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT) see www.iso.org/iso/foreword.html.
In the IEC, see www.iec.ch/understanding-standards.
This document was prepared by Joint Technical Committee ISO/IEC JTC1, Information technology,
Subcommittee SC 32, Data management and interchange.
A list of all parts in the ISO/IEC 19583 series can be found on the ISO and IEC websites.
Any feedback or questions on this document should be directed to the user’s national standards
body. A complete listing of these bodies can be found at www.iso.org/members.html and
www.iec.ch/national-committees.
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ISO/IEC 19583-26:2026(en)
Introduction
The ISO/IEC 11179 series addresses the semantics of data, the representation of data, and the registration
of the descriptions of that data. At the time of the publication of ISO/IEC 11179-3:2013 to which this
document refers, ISO/IEC 11179 was a six-part series of standards, whose conceptual model was specified in
ISO/IEC 11179-3. Since this time, part three has continued to be refined, developed and factorized.
ISO/IEC 11179-3:2013 does not define a physical implementation and thus need not be implemented as
specified, which makes exchanging content between even compliant registries difficult. A common physical
implementation is required if automatic content exchange is to be achieved.
ISO/IEC 11179-3:2013 representation in W3C XML Schema is such a physical representation. It also provides
a potential model for its implementation as an XML database focused on units of content that are readily
created and maintained – particularly if reasoning over the ‘meaning’ of that content can be delegated to an
accompanying RDF database as described in ISO/IEC TR 19583-24.
As the adoption of 11179 MDRs expands, metadata registries will need to reuse and extend definitions
from other MDRs, together with definitions reflecting local information types. The schema allows metadata
registry content to be exchanged in a standard format regardless of the kind of registry software in use.
The schema is presented in ‘Venetian Blind’ style, where each of the components of the model are rendered
as reusable types. These types are assembled into discrete documents suitable for creation and exchange.
The main body of the document describes the schema together with the principles and conventions that
were followed to map classes, attributes, and associations of the conceptual model into an acyclic, directed
graph suitable for an unambiguous document-based representation. The schema is specified in three
parts in Annex B, C and D. Additionally, Annex A describes the relationship between the 2013 and current
editions of ISO/IEC 11179-3, ISO/IEC 11179-31 and ISO/IEC 11179-32; Annex E suggests a schema derived
from Annex B and C to support a XML database system holding ISO/IEC 11179 content; Annex F contains a
compliant, example message communicating data elements between two registries.
Where direct reference is made to class, attribute and relationship names from models described in
parts of ISO/IEC 11179, class names are emboldened with initial capital letters and have spaces replaced
by underscore characters, attribute names are enboldened in lower case and have spaces replaced by
underscore characters, and relationship names are italicised in lower case with spaces replaced by
underscore characters.
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International Standard ISO/IEC 19583-26:2026(en)
Information technology — Concepts and usage of metadata —
Part 26:
XML for representation of ISO/IEC 11179-3:2013 content
1 Scope
This document specifies the structure of ISO/IEC 11179-3:2013 representation in W3C XML Schema
suitable for communication of content between compliant registries. The schema described in this
document will implement a class and attribute vocabulary that matches the conceptual model presented
in ISO/IEC 11179-3:2013 in W3C XML Schema format. The purpose of the schema is for the exchange of
compliant metadata, and to support the validation of messages exchanged between registries. It is not
intended for the communication of data element metadata alongside the data to which the metadata refers.
The document specifes the schema and the principles and conventions that were followed to map classes,
attributes, and associations of the conceptual model into an acyclic, directed graph suitable for an
unambiguous document-based representation.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements 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.
1)
ISO/IEC 11179-3:2013 , Information technology — Metadata registries (MDR) Part 3: Registry metamodel and
basic attributes
2)
ISO/IEC 11179-6:2015 , Information technology — Metadata registries (MDR) Part 6: Registration
W3C XML Schema https:// www .w3 .org/ XML/ Schema
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO/IEC 11179-3:2013,
ISO/IEC 11179-6:2015 and the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1 General computing terms
3.1.1
extension
feature not defined by this document
1) Withdrawn and replaced by ISO/IEC 11179-3:2023.
2) Withdrawn and replaced by ISO/IEC 11179-6:2023.
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3.1.2
namespace
classification scheme that permits a given name to identify multiple objects that are distinguished by context
[SOURCE: ISO/IEC 39075:2024, 3.6.5]
3.1.3
namespace prefix
short name to uniquely identify the namespace
[SOURCE: ISO 24531:2013, 4.40]
3.1.4
schema
formal definition of a model
[SOURCE: ISO 19101-1:2014, 4.1.34]
3.2 Terms relating to XML Schema and RDF
3.2.1
internationalized resource identifier
IRI
sequence of characters that conforms to the syntax defined in RFC 3987
[SOURCE: ISO/IEC 19788-7:2019, 3.7, modified – domain and Note to entry deleted.]
3.2.2
World Wide Web Consortium
W3C
international community that develops open standards to ensure the long-term growth of the Web
[SOURCE: ISO 8:2019, 3.5.6]
3.2.3
XML schema
language for describing the structure and constraining the contents of XML documents
[SOURCE: ISO 25720:2009, 4.32]
3.2.4
resource
element from a universe of discourse denoted by an IRI (3.2.2)
3.2.5
Resource Description Framework
RDF
W3C (3.2.2) standard defining a formal syntax and semantics for expressing descriptions of resources (3.2.4)
that can be represented as a directed data graph
[SOURCE: ISO/IEC TR 19583-24:2025, 3.3.6, modified – references made local to this document and Note to
entry deleted.]
4 Conformance
4.1 Overview of conformance
Conformance claims shall specify a degree of conformance. Where the schemas are used to validate a
message, the degree of conformance shall be defined as described in 4.2. Where these schemas are used
as part of a data model for an XML implementation of a registry, conformance may additionally be claimed
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against ISO/IEC 11179-3:2013. While such conformance must be established on a case-by-case basis, it is to
be expected that such a registry will be able to claim to be ‘conforming’.
4.2 Degree of conformance
4.2.1 General
The distinction between “strictly conforming” and “conforming” implementations is necessary to address
the simultaneous needs for interoperability and extensions. This document describes specifications that
promote interoperability.
A strictly conforming implementation can be limited in usefulness but is maximally interoperable with
respect to this document. A conforming implementation can be more useful but can be less interoperable
with respect to this document.
4.2.2 Strictly conforming implementations
A strictly conforming registry shall emit XML documents that validate against the schema described
in this document without error when using a validator that is fully conformant with the W3C XSD 1.1
Recommendation of 5 April 2013.
4.2.3 Conforming implementations
A conforming registry shall emit XML documents that use the namespace, document, element and attribute
names together with the containment hierarchy described in this document. It need not meet the explicit
cardinality requirements of the schema; it may include extra elements and attributes in other namespaces
where extension elements are allowed. Mandatory elements and attributes may be omitted entirely, or
repeated in greater numbers than the schema allows.
5 Use cases, modelling principles and mapping conventions
5.1 General
The contained schema is intended principally for the exchange of Data Element and Value Domain content
between registries and modelling environments and for the use of such content in the configuration
of information systems. It may also be used – in part or as a whole – as a foundation of a compliant XML
database implementation of ISO/IEC 11179-3:2013.
There are three broad use cases for information exchange between registries:
a) detailed replication of large amounts of content between ISO/IEC 11179-3:2013 compliant registries
whose audiences are in agreement on the conceptualisation of the data elements exchanged;
b) smaller scale exchange of data elements between registries in partly overlapping domains that have
different conceptual models;
c) exchange of data element content between configurable information systems or local data dictionaries
and registries that have no published conceptual models and registries in their domain.
The first use case requires a sophisticated way of exchanging a broad range of content and its
interrelationships. ISO/IEC TR 19583-24 describes a resource description framework schema (RDFS) for
ISO/IEC 11179-3:2013, which is capable of faithfully representing the ISO/IEC 11179-3:2013 conceptual
model with few compromises, and this is recommended here.
For the second, while understanding the original context of data element and value domain content is
important, imported content will be relocated in the conceptual model of the target registry. An example
here is the reuse of specific data element content for the Identification of Medicinal Products (ISO 11615;
ISO 11616; ISO 11238) in registries whose audiences run pharmacies and prescribe and administer drugs.
It is not necessarily the case that the Conceptual Domains, Object Classes, Properties and Data Element
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Concepts that support such data elements for regulatory purposes translate directly to ones that help people
reuse product identification information in patient care.
For the last use case content will be partial – data element names, units of measure, datatypes, valid values
and meanings, and versioning information will be present, but rigorous notions corresponding to the upper
half of ISO/IEC 11179-3:2013, Figure 11 (i.e. data element concept and conceptual domain) will not. Examples
include survey systems – such as Google Forms, SurveyMonkey, RedCap OpenClinica – and more generally
from information systems where user-facing forms or data elements may be configured within the product
as part of its deployment.
Where the schema is intended to support the development of an XML database, the design fits in with an
overall approach where the model is factored into units that map to content creation workflows, and for each
identified item there is one (or a small number) of related content creation forms. In such an implementation,
XQuery would be used to navigate from shared leaf classes, and to hide administrative metadata from
summary views such as content maps, tree browsers, alphabetic listings and search forms. Implementers
will need to provide simple additional schemas that declare XML elements for the types they wish to offer to
the users as content creation points, or alternatively they could include these element definitions in a choice
element in a single schema.
The goal of ISO/IEC 11179-3 Representation in XML Schema is to provide a near complete and faithful mapping
of all classes, attributes, and associations of the ISO/IEC 11179-3:2013 conceptual model to a schema based
on W3C XML Schema language in a more deterministic, fixed model that can be easily deployed, focused on
creating, managing and exchanging Data Element and Value Domain content. The assumptions made in the
translation of the conceptual model into a physical representation are outlined in general within this clause,
and in specific in the narrative in Clause 6.
5.2 Directionality and indirection of relationships
In ISO/IEC 11179-3:2013, relationship directionality and end point visibility are not specified, and there
are many points in the model where it is possible to create content that indirectly references itself either
immediately or as part of larger cyclic structures. While direct implementation of such models is possible
in XML Schema, additional code – Schematron rules or an XForm/XQuery API – is required to ensure
documents that validate against the schema make sense. To avoid this problem, the schemas specified here
assert directionality, and implement certain important relationships as references.
The default directionality can be generally stated as having Data Element, Value Domain, Data Element
Concept and Conceptual Domains as the base units of content and exchange, with reference relationships
between these classes. It is assumed that these items will be ‘identified items’ according to the definition of
ISO/IEC 11179-3:2013, and thus the reference is to the item identifier for that item. Within each of these units,
dependent content is represented as a hierarchy of nodes. An exception to this principle is made for value
meanings where a choice between referring to the meaning in a separate Conceptual Domain definition, or
including the meaning directly in the Value Domain is offered to implementers who have the third use case
in 5.1.
The model additionally defines many shared classifiers including Context, Object Class, Property, and Units
of Measure. To avoid duplication of this content at every point of reference in the XML document, these are
also required to be identified items. However, for the sake of brevity these classifiers are strictly leaves,
without explicit navigability back to the related classes: for example each Data Element Concept instance that
is classified by a particular Object Class instance is not enumerated in that Object Class instance. Reverse
links can be computed using XQuery inside an XML database representation. Additionally it is possible to
separately specify Organisations, Individuals and Contacts for large exchanges of content between registries.
5.3 Schema documents
Three normative schema documents are presented in Annexes B, C and D:
a) iso11179-3_common_facilities.xsd presents the types described as common facilities in
ISO/IEC 11179-3:2013. This schema document is widely applicable to standards from the 11179 and
19763 families (Annex B) and is declared in the ISO/IEC 11179-3 namespace.
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ISO/IEC 19583-26:2026(en)
b) iso11179-3_four_corners.xsd assembles the common facilities into the main content types of an
ISO/IEC 11179-3:2013 compliant registry (Annex C) and is declared in the ISO/IEC 11179-3 namespace.
c) iso11197-3_message.xsd imports the previous schema in the ISO/IEC 11179-3 namespace to define
a document structure for exchanging content between compliant registries (Annex D), new message
elements are declared in the ISO/IEC 19583-26 namespace.
A further, informative schema demonstrating how schemas (a) and (b) can be used to implement an XML
database is presented in Annex E, imported types are in the ISO/IEC 11179-3 namespace, root elements for
database content are declared in the the ISO/IEC 19583-26 namespace.
An account of differences between ISO/IEC 11179-3:2013 and the current 2023 versions is presented in
Annex A (informative), and a list of any class or attribute names that have been added or changed in these
schemas is presented in Annex F.
All four schemas are available in file form for download at https:// standards .iso .org/ iso -iec/ 19583/ -26/ ed
-1/ en
5.4 Schema style
The style of the schema is to define a large number of global type definitions at various levels of complexity
and integration and to make these specific with local element definitions that tightly specify the kinds
of elements that can be used to compose documents. As such, a Postal_Address type is defined without
presumption that a root element of type Postal_Address will actually appear as a stand-alone XML document,
it being left to the user as to how these types are presented as a collection of documents.
The schema is presented in three parts: a ‘common facilities’ schema containing global base type definitions
for use in all implementations; a ‘four corners’ schema that assembles these common facilities into a selection
of types most useful for the creation of content interchange messages, and an overarching ‘message’ schema
that assembles these types into an XML document that is used to exchange content.
It is expected that the underlying implementations of ISO/IEC 11179-3 that registry users will interact
with to create content will be most often relational, with XML representations used for content exchange
and RDF representations used for computation. Therefore, these schemas do not make use of specific XML
capabilities such as ID/IDREF for the reuse of content by reference, or any of the proposed mechanisms for
content inclusion such as XInclude. XML database implementers may wish to modify elements of the schemas
to utilise such features in their implementation platform.
5.5 Schema conventions
The following conventions have been used for mapping the ISO/IEC 11179-3:2013 model elements to W3C
XML Schema.
Every model element is represented in W3C XML Schema in the namespace http:// standards .iso .org/ iso
-iec/ 11179/ -3/ ed -3/ en/ and is abbreviated with the namespace prefix iso-11179, except for those model
elements introduced by this document, which are in the https:// standards .iso .org/ iso -iec/ 19583/ -26/ ed -1/
en/ namespace.
Every class of ISO/IEC 11179-3:2013 is represented by a simple or complex type. Names maintain the
capitalization and underscores as specified in the parent standard.
6 Overview of ISO/IEC 11179-3:2013 Representation in XML Schema
6.1 General
ISO/IEC 11179-3:2013 specifies ‘item types’ such that later classes can be typed by one or more of these
types. Each of these item types is rendered as an xsd:group since W3C XML Schema does not support
multiple inheritance. e.g. Identified_Item; Designatable_Item.
PROOF/ÉPREUVE
© ISO/IEC 2026 – All rights reserved
ISO/IEC 19583-26:2026(en)
Certain relationships between classes have been replaced by reference to their scoped identifier rather than
by inclusion of content, e.g. Namespace from Scoped_Identifier, designation_context from Designation.
6.2 Basic Types metamodel region (ISO/IEC 11179-3:2013, 6.2)
Basic types defined in ISO/IEC 11179-3:2013 are declared as simple types, indirected from the corresponding
XML base datatypes. It is expected that the base datatypes will function correctly in interchange and
database use cases, but indirection allows users of the schema components to further restrict the base types
if required, such as disallowing symbols in a datatype expected to hold a filename.
6.3 Basic Classes metamodel region (ISO/IEC 11179-3:2013, 6.3)
Basic classes are faithfully represented from the standard.
6.4 Identification metamodel region (ISO/IEC 11179-3:2013, 7.2)
It is at this point that the model in ISO/IEC 11179-3:2013 becomes more conceptual with the implementer
invited to decide what items to identify, name and define, together with some structures that have the
potential to be recursive. This implementation has made the following assumptions:
— Namespaces are required to be identified and referenced by identifier when used. To avoid the recursive
relationship, attributes for identifier and version have been directly included in the type.
— Scoped identifiers exist as part of an identified item that refers to their namespace by reference, rather
than existing within a namespace node, as implied by a simple reading of the class diagram.
Identified_Item is rendered from the standard as a schema group for inclusion in later classes. It is assumed
in this schema that Scoped_Identifier will not exist separately of an Identified_Item.
6.5 Designation and Definition metamodel region (ISO/IEC 11179-3:2013, Clause 7)
This implementation has made the following assumptions:
— Naming Conventions are identified items, instances are referenced by their scoped identifiers.
— Context is set to be both an identified item and a designatable item. The recursive relationships to
designation and definition contexts have been removed by localising appropriate attributes from the
definition and designation classes within the Context type.
— Relationships between designations have been supported in the following way: it is possible to include
a specific definition local to a designation, and a designation may be listed as a designation_heading,
assuming that the specific definition only has context alongside its designation, and that designations
are unique.
6.6 Registration metamodel region (ISO/IEC 11179-3:2013, Clause 8)
Implementation of the registration and administration classes is mostly as described in the standard except
for the implementation of relationships between registered item, administered item and attached item.
The combination of the inheritance relationship between registered, administered and attached item and
the composition relationship between administered and attached item creates errors in later parts of the
schema if both the administered and attached item types contain registered item attributes. Implementation
of the inheritance relationship is deferred until the introduction of the ‘Metadata_Item’ type to encapsulate
the notions of identification, naming, classification, registration, administration and attachment.
6.7 Concepts package (ISO/IEC 11179-3:2013, Clause 9), Binary Relations package (ISO/IEC
11179-3:2013, Clause 10)
As modelled, the concepts and binary relations packages contain the greatest scope for recursion and
repetition of content when implementing the conceptual model as a hierarchical structure. Since it is best
PROOF/ÉPREUVE
© ISO/IEC 2026 – All rights reserved
ISO/IEC 19583-26:2026(en)
practice for every concept in a concept system to be explicitly identified and named, this implementation has
taken the opportunity to replace many of the relationships between classes in this part of the model with
scoped identifier references, with attributes at both endpoints of the relationship.
It is also best practice to administer/publish a concept system as a complete entity, rather than in pieces.
Thus administration and attachment are reserved for the Concept_System type, rather than being applied to
its components.
6.8 Metadata Item Type
The overall approach of the modelling in ISO/IEC 11179-3:2013 is to define a number of conceptual
‘types’ that may be applied to content classes. Thus identification, classification, designation, registration,
administration and attachment all have associated types that are applied by the implementer according to
the policies specified by the registrar. This allows the standard to support a wide variety of registries from
those that create and maintain content in detail to ones that aggregate content that is registered elsewhere.
W3C XML schema does not support multiple inheritance. The approach taken has been to declare an
abstract class of ‘Metadata_Item’ – which can optionally be identified, named, classified, registered and
either administered or attached – and for the classes in the data description class to inherit from this. This
simplifies the definition of types in the data description package, and provides a basis for further work
developing schemas for other parts of ISO/IEC 11179 together with the ISO/IEC 19763 family that share
these notions.
6.9 Data Description package (ISO/IEC 11179-3:2013, Clause 11)
6.9.1 General
The approach taken to the data description package is to broadly support content kinds according to the ‘four
corners’ high level conceptual model for the data description package (ISO/IEC 11179-3:2013, Figure 11) – a
complex type is defined for each concrete class at the four corners. Implementers of XML databases can find
this causes performance issues with enumerated conceptual and value domains and may wish to factorize
these classes differently.
One issue with an XML schema implementation of the data description package is in the choice of class to
inherit from. Object Class, Property, Data Element Concept, Conceptual Domain and Value Meaning are
all kinds of Concept, but unlike concepts in a concept system – which are administered as a system – they
often require individual administration. This implementation treats these objects as being distinct from
any general concept system – i.e. either designatable or metadata items – with an additional, optional
relationship to a concept in a concept system. This is semantically safest – an assertion of association from
one of these objects to a concept cannot dislocate the target concept from its proper place in the concept
system, whereas stating equivalence between – say – a value meaning and a concept introduces to the
concept system associations with the other value meanings and the containing conceptual domain that risks
changing the concept’s meaning.
6.9.2 Measurement metamodel region (ISO/IEC 11179-3:2013, 11.4)
Since value domains measured with comparable/convertible units will usually fall naturally into the same
conceptual domain, a registry may simply maintain a flat list of units of measure and exchange these as
required when they exchange value domains. If more order is desired, since conceptually different units
of measure may share the same dimension (e.g. frequency, angular velocity), Measure_Class is the natural
containing class of this region, the compromise being that this prevents units of measure belonging to more
than one measure class.
6.9.3 Data Element Concept metamodel region (ISO/IEC 11179-3:2013, 11.2)
Data element concepts, object classes and properties are all set to be kinds of Metadata_Item, with an
additional concept reference to represent the assertion of association/equivalence with a concept in a
registered concept system.
PROOF/ÉPREUVE
© ISO/IEC 2026 – All rights reserved
ISO/IEC 19583-26:2026(en)
6.9.4 Conceptual and Value Domain metamodel region (ISO/IEC 11179-3:2013, 11.3)
Conceptual and Value Domains are set to be kinds of Metadata_Item, with an additional concept reference
to represent the assertion of association/equivalence with a concept in a registered concept system. Value
Meanings include groups for identification and designation, and additionally also have a concept reference.
It is assumed that the set of Value Meanings are part of the Conceptual Domain and thus share their
administration record, the same assumption applies to Permissible Values and Value Domains. However, the
option is available to exchange meanings within a Value Domain where Conceptual Domains are unavailable.
6.9.5 Data_Element metamodel region (ISO/IEC 11179-3:2013, 11.5)
Data Elements, their derivations, and derivation rules themselves each are set to be Metadata Items with
their own administration records.
6.10 ISO/IEC 11179-3:2013 Message and Database Schema
Finally, the types defined in 6.9 are brought together into a ‘metadata bundle’, a simple sequence of nodes of
the main content kinds in an ISO/IEC 11179-3:2013 registry, together with the registry specification and the
date and time of export (see Annex C). An example database schema is also offered in Annex D, although it
is anticipated that the basic components of ISO/IEC 11179-3:2013, and the schema elements suggested here,
could be brought together in many different ways.
PROOF/ÉPREUVE
© ISO/IEC 2026 – All rights reserved
ISO/IEC 19583-26:2026(en)
Annex A
(informative)
Summary of differences between ISO/IEC 11179-3:2013
and ISO/IEC 11179-3:2023, ISO/IEC 11179-31:2023 and
ISO/IEC 11179-32:2023
A.1 Overview
This document is targeted at ISO/IEC 11179-3:2013, which has been superseded by ISO/IEC 11179-3:2023
and other parts of the ISO/IEC 11179 series, such as ISO/IEC 11179-31:2023 and ISO/IEC 11179-32:2023.
This annex provides an overview of the differences.
A.2 Modularization of ISO/IEC 11179-3:2013
In the 2023 edition, ISO/IEC 11179-3:2013 has been split into multiple parts to make it more manageable.
The following are the new parts:
— ISO/IEC 11179-30 Basic attributes of metadata;
— ISO/IEC 11179-31 Metamodel for data specification registration;
— ISO/IEC 11179-32 Metamodel for concept system registration.
A.3 Simplification of the UML metamodel
Some changes were made in the 2023 edition to simplify the UML model:
— elimination of the use of UML stereotypes;
— addition of an explicit 'Item' class as the superclass of all types of registry items;
— removal of role names on associations;
— removal of redundant specification of attributes and associations in the text.
A.4 Refactoring of some of the packages to reduce dependencies
Some changes were made in the 2023 edition to reduce dependencies among packages:
— moving the Concept class to the Basic and Core package where it is referenced from multiple metamodel
regions, including: the Data Specification package in ISO/IEC 11179-31, the Concept System package in
ISO/IEC 11179-32, the Data Set package in ISO/IEC 11179-33 and the Model package in ISO/IEC 11179-35;
— moving the Context class to the Basic and Core package where it is referenced from the Designation and
Definition package in ISO/IEC 11179-3:2023, the Data Specification package in ISO/IEC 11179-31 and the
Data Set package in ISO/IEC 11179-33;
— moving the Slot class to the Basic and Core package, a more appropriate location than the Identification
package;
— restoring a Classification region, based on the style of ISO/IEC 11179-3:2003, to remove dependency on
the Concept System region for classification.
PROOF/ÉPREUVE
© ISO/IEC 2026 – All rights reserved
ISO/IEC 19583-26:2026(en)
A.5 Use of UML stereotypes in ISO/IEC 11179-3:2013
UML stereotypes were used in ISO/IEC 11179-3:2013. Each of these types (except Registered_Item which is
abstract and cannot be instantiated) can be applied to any of the instances of metadata items in the registry.
In ISO/IEC 11179-3:2023, the use of stereotypes has been replaced by subclassing from the superclass Item,
which is specified in the new Core metamodel region and which did not exist in the 2013 edition.
A.6 Differences in the Identification metamodel region
In the 2013 edition, Identified_Item is a <> which needs to be applied to instances of metadata items
that are to be identified. In the 2023 edition, Identified_Item is a regular class related to Item by the item_
identification association.
Also, Slot in the 2013 edition is related to Identified_Item, whereas in the 2023 edition it is related to Item
in the Core metamodel region.
A.7 Differences in the Designation and Definition metamodel region
In the 2013 edition, Designatable_Item is <> which needs to be applied to instances of metadata
items that are to be designated or defined;
In the 2023 edition, Designatable_Item is replaced by Item, which can be directly related to the Designation
and Definition classes;
In the 2013 edition, designation_definition_pairing is a simple association between Designation and
Definition. In the 2023 edition, Designation_Definition_Pairing is an association class, which is also
associated with Context, and has an attribute acceptability.
A.8 Differences in the Registration metamodel region
In the 2013 edition, Administered_Item and Attached_Item are <> which need to be applied to
instances of metadata items that are to be administered or attached. In the 2023 edition, Administered_
Item and Attached_Item are regular classes which are associated with Item through the item_identification
association of the grandparent class Identified_Item;
In the 2013 edition, Registration is an association class, with a registration_state attr
...

ISO/IEC DIS PRF 19583-26:2024(en)
ISO/IEC JTC 1/SC 32/WG 2
Date:2024-10-25
Secretariat: ANSI
Date: 2026-03-06
Information technology – — Concepts and usage of metadata – —
Part 26:
XML for representation of ISO/IEC 11179-3:2013 content
FDIS stage
© ISO/IEC 2024, 2026Published in Switzerland
All rights reserved. Unless otherwise specified, or required in the context of its implementation, 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
CP 401 • Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel.Phone: + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
ISO/IEC DISPRF 19583-26:20242026(en)
Contents
Foreword . iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
3.1 General computing terms . 2
3.2 Terms relating to XML Schema and RDF . 2
4 Conformance . 3
4.1 Overview of conformance . 3
4.2 Degree of conformance . 3
5 Use cases, modelling principles and mapping conventions . 3
5.1 General . 3
5.2 Directionality and indirection of relationships . 4
5.3 Schema documents . 5
5.4 Schema style . 5
5.5 Schema conventions . 6
6 Overview of ISO/IEC 11179-3:2013 Representation in XML Schema . 6
6.1 General . 6
6.2 Basic Types metamodel region (ISO/IEC 11179-3:2013, 6.2) . 6
6.3 Basic Classes metamodel region (ISO/IEC 11179-3:2013, 6.3) . 6
6.4 Identification metamodel region (ISO/IEC 11179-3:2013, 7.2). 6
6.5 Designation and Definition metamodel region (ISO/IEC 11179-3:2013, Clause 7) . 7
6.6 Registration metamodel region (ISO/IEC 11179-3:2013, Clause 8) . 7
6.7 Concepts package (ISO/IEC 11179-3:2013, Clause 9), Binary Relations package (ISO/IEC
11179-3:2013, Clause 10) . 7
6.8 Metadata Item Type . 7
6.9 Data Description package (ISO/IEC 11179-3:2013, Clause 11) . 8
6.10 ISO/IEC 11179-3:2013 Message and Database Schema . 9
Annex A (informative) Summary of differences between ISO/IEC 11179-3:2013 and ISO/IEC
11179-3:2023, ISO/IEC 11179-31:2023 and ISO/IEC 11179-32:2023 . 10
Annex B (normative) Common Facilities Schema . 14
Annex C (normative) ‘Four Corners’ Schema . 38
Annex D (normative) Message Schema . 49
Annex E (informative) Example Database Schema . 53
Annex F (informative) Class, attribute and relation name correspondence . 55
Bibliography . 57

© ISO/IEC 2024 2026 – All rights reserved
iii
Foreword
ISO (the International Organization for Standardization) and IEC (the International Electrotechnical
Commission) form the specialized system for worldwide standardization. National bodies that are members
of ISO or IEC participate in the development of International Standards through technical committees
established by the respective organization to deal with particular fields of technical activity. ISO and IEC
technical committees collaborate in fields of mutual interest. Other international organizations, governmental
and non-governmental, in liaison with ISO and IEC, also take part in the work.
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
document 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 or www.iec.ch/members_experts/refdocs).
ISO and IEC draw attention to the possibility that the implementation of this document may involve the use of
(a) patent(s). ISO and IEC take no position concerning the evidence, validity or applicability of any claimed
patent rights in respect thereof. As of the date of publication of this document, ISO and IEC had not received
notice of (a) patent(s) which may be required to implement this document. However, implementers are
cautioned that this may not represent the latest information, which may be obtained from the patent database
available at www.iso.org/patents and https://patents.iec.ch. ISO and IEC shall not be held responsible for
identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT) see www.iso.org/iso/foreword.html.
In the IEC, see www.iec.ch/understanding-standards.
This document was prepared by Joint Technical Committee ISO/IEC JTC1, Information technology,
Subcommittee SC 32, Data management and interchange.
A list of all parts in the ISO/IEC 19583 series can be found on the ISO and IEC websites.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html and www.iec.ch/national-
committees.
iv
ISO/IEC DISPRF 19583-26:20242026(en)
Introduction
The ISO/IEC 11179 series addresses the semantics of data, the representation of data, and the registration of
the descriptions of that data. At the time of the publication of ISO/IEC 11179-3:2013 to which this document
refers, ISO/IEC 11179 was a six-part standardseries of standards, whose conceptual model was specified in
ISO/IEC 11179-3. Since this time, part three has continued to be refined, developed and factorized.
ISO/IEC 11179-3:2013 does not define a physical implementation and thus need not be implemented as
specified, which makes exchanging content between even compliant registries difficult. A common physical
implementation is required if automatic content exchange is to be achieved.
ISO/IEC 11179-3:2013 representation in W3C XML Schema is such a physical representation. It also provides
a potential model for its implementation as an XML database focused on units of content that are readily
created and maintained – particularly if reasoning over the ‘meaning’ of that content can be delegated to an
accompanying RDF database as described in ISO/IEC TR 19583-24.
As the adoption of 11179 MDRs expands, metadata registries will need to reuse and extend definitions from
other MDRs, together with definitions reflecting local information types. The schema allows metadata registry
content to be exchanged in a standard format regardless of the kind of registry software in use.
The schema is presented in ‘Venetian Blind’ style, where each of the components of the model are rendered as
reusable types. These types are assembled into discrete documents suitable for creation and exchange. The
main body of the document describes the schema together with the principles and conventions that were
followed to map classes, attributes, and associations of the conceptual model into an acyclic, directed graph
suitable for an unambiguous document-based representation. The schema is specified in three parts in
Annex BAnnex B, C, C and DD. . Additionally: Annex A, Annex A describes the relationship between the 2013
and current editions of ISO/IEC 11179-3, ISO/IEC 11179-31, and ISO/IEC 11179-32; Annex EAnnex E suggests
a schema derived from Annex BAnnex B and CC to support a XML database system holding ISO/IEC 11179
content; Annex FAnnex F contains a compliant, example message communicating data elements between two
registries.
Where direct reference is made to class, attribute and relationship names from models described in parts of
ISO/IEC 11179, class names are emboldened with initial capital letters and have spaces replaced by
underscore characters, attribute names are enboldened in lower case and have spaces replaced by underscore
characters, and relationship names are italicised in lower case with spaces replaced by underscore characters.
© ISO/IEC 2024 2026 – All rights reserved
v
DRAFT International Standard ISO/IEC DIS 19583-26:2024(en)

Information technology – — Concepts and usage of metadata – —
Part 26:
XML for representation of ISO/IEC 11179-3:2013 content
1 Scope
This document specifies the structure of ISO/IEC 11179-3:2013 representation in W3C XML Schema suitable
for communication of content between compliant registries. The schema described in this document will
implement a class and attribute vocabulary that matches the conceptual model presented in ISO/IEC 11179-
3:2013 in W3C XML Schema format. The purpose of the schema is for the exchange of compliant metadata,
and to support the validation of messages exchanged between registries. It is not intended for the
communication of data element metadata alongside the data to which the metadata refers.
The document specifes the schema and the principles and conventions that were followed to map classes,
attributes, and associations of the conceptual model into an acyclic, directed graph suitable for an
unambiguous document-based representation.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements 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.
11)
ISO/IEC 11179--3:2013, , Information technology — Metadata registries (MDR) Part 3: Registry metamodel
and basic attributes
22)
ISO/IEC 11179--6:2015, , Information technology — Metadata registries (MDR) Part 6: Registration
W3C XML Schema https://www.w3.org/XML/Schema
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO/IEC 11179--3:2013,
ISO/IEC 11179--6:2015 and the following apply.
ISO and IEC maintain terminologicalterminology databases for use in standardization at the following
addresses:
— — ISO Online browsing platform: available at https://www.iso.org/obp

Cancelled and replaced by ISO/IEC 11179-3:2023.
1)
Withdrawn and replaced by ISO/IEC 11179-3:2023.

Cancelled and replaced by ISO/IEC 11179-6:2023.
2)
Withdrawn and replaced by ISO/IEC 11179-6:2023.

© ISO/IEC 2024 – All rights reserved

— — IEC Electropedia: available at https://www.electropedia.org/
3.1 General computing terms
3.1.1 3.1.1
extension
feature not defined by this document
3.1.2 3.1.2
namespace
classification scheme that permits a given name to identify multiple objects that are distinguished by context
[SOURCE: ISO/IEC 39075:2024, 3.6.5]
3.1.3 3.1.3
namespace prefix
short name to uniquely identify the namespace
[SOURCE: ISO 24531:2013, 4.40]
3.1.4 3.1.4
schema
formal definition of a model
[SOURCE: ISO 19101-1:2014, 4.1.34]
3.2 Terms relating to XML Schema and RDF
3.2.1 3.2.1
internationalized resource identifier
IRI
sequence of characters that conforms to the syntax defined in RFC 3987
[SOURCE: ISO/IEC 19788-7:2019, 3.7, modified – domain and Note to entry deleted.]
3.2.2 3.2.2
World Wide Web Consortium
W3C
international community that develops open standards to ensure the long-term growth of the Web
[SOURCE: ISO 8:2019, 3.5.6]
3.2.3 3.2.3
XML schema
language for describing the structure and constraining the contents of XML documents
[SOURCE: ISO 25720:2009, 4.32]
3.2.4 3.2.4
resource
element from a universe of discourse denoted by an IRI (3.2.2(3.2.2))
ISO/IEC DISPRF 19583-26:20242026(en)
3.2.5 3.2.5
Resource Description Framework
RDF
W3C (3.2.2(3.2.2)) standard defining a formal syntax and semantics for expressing descriptions of resources
(3.2.4(3.2.4)) that can be represented as a directed data graph
[SOURCE: ISO/IEC TR 19583-24:2025, 3.3.6, modified – references made local to this document and Note to
entry deleted.]
4 Conformance
4.1 Overview of conformance
Conformance claims shall specify a degree of conformance. Where the schemas are used to validate a message,
the degree of conformance shall be defined as described in 4.24.2. Where these schemas are used as part of a
data model for an XML implementation of a registry, conformance may additionally be claimed against ISO/IEC
11179-3:2013. While such conformance must be established on a case-by-case basis, it is to be expected that
such a registry will be able to claim to be ‘conforming’.
4.2 Degree of conformance
4.2.1 General
The distinction between “strictly conforming” and “conforming” implementations is necessary to address
the simultaneous needs for interoperability and extensions. This document describes specifications that
promote interoperability.
A strictly conforming implementation can be limited in usefulness but is maximally interoperable with
respect to this document. A conforming implementation can be more useful but can be less interoperable with
respect to this document.
4.2.2 Strictly conforming implementations
A strictly conforming registry shall emit XML documents that validate against the schema described in this
standarddocument without error when using a validator that is fully conformant with the W3C XSD 1.1
Recommendation of 5 April 2013.
4.2.3 Conforming implementations
A conforming registry shall emit XML documents that use the namespace, document, element and attribute
names together with the containment hierarchy described in this document. It need not meet the explicit
cardinality requirements of the schema; it may include extra elements and attributes in other namespaces
where extension elements are allowed. Mandatory elements and attributes may be omitted entirely, or
repeated in greater numbers than the schema allows.
5 Use cases, modelling principles and mapping conventions
5.1 General
The contained schema is intended principally for the exchange of Data Element and Value Domain content
between registries and modelling environments and for the use of such content in the configuration of
information systems. It may also be used – in part or as a whole – as a foundation of a compliant XML database
implementation of ISO/IEC 11179-3:2013.
There are three broad use cases for information exchange between registries:
© ISO/IEC 2024 2026 – All rights reserved
a) a) detailed replication of large amounts of content between ISO/IEC 11179-3:2013 compliant
registries whose audiences are in agreement on the conceptualisation of the data elements exchanged;
b) b) smaller scale exchange of data elements between registries in partly overlapping domains that
have different conceptual models;
c) c) exchange of data element content between configurable information systems or local data
dictionaries and registries that have no published conceptual models and registries in their domain.
The first use case requires a sophisticated way of exchanging a broad range of content and its
interrelationships. ISO/IEC TR 19583-24 describes a resource description framework schema (RDFS) for
ISO/IEC 11179-3:2013, which is capable of faithfully representing the ISO/IEC 11179-3:2013 conceptual
model with few compromises, and this is recommended here.
For the second, while understanding the original context of data element and value domain content is
important, imported content will be relocated in the conceptual model of the target registry. An example here
is the reuse of specific data element content for the Identification of Medicinal Products (ISO 11615:2017; ISO
11616:2017; ISO 11238:2018) in registries whose audiences run pharmacies and prescribe and administer
drugs. It is not necessarily the case that the Conceptual Domains, Object Classes, Properties and Data Element
Concepts that support such data elements for regulatory purposes translate directly to ones that help people
reuse product identification information in patient care.
For the last use case content will be partial – data element names, units of measure, datatypes, valid values
and meanings, and versioning information will be present, but rigorous notions corresponding to the upper
half of ISO/IEC 11179-3:2013, Figure 11 (i.e. data element concept and conceptual domain) will not. Examples
include survey systems – such as Google Forms, SurveyMonkey, RedCap OpenClinica – and more generally
from information systems where user-facing forms or data elements may be configured within the product as
part of its deployment.
Where the schema is intended to support the development of an XML database, the design fits in with an
overall approach where the model is factored into units that map to content creation workflows, and for each
identified item there is one (or a small number) of related content creation forms. In such an implementation,
XQuery would be used to navigate from shared leaf classes, and to hide administrative metadata from
summary views such as content maps, tree browsers, alphabetic listings and search forms. Implementers will
need to provide simple additional schemas that declare XML elements for the types they wish to offer to the
users as content creation points, or alternatively they could include these element definitions in a choice
element in a single schema.
The goal of ISO/IEC 11179-3 Representation in XML Schema is to provide a near complete and faithful
mapping of all classes, attributes, and associations of the ISO/IEC 11179-3:2013 conceptual model to a schema
based on W3C XML Schema language in a more deterministic, fixed model that can be easily deployed, focused
on creating, managing and exchanging Data Element and Value Domain content. The assumptions made in the
translation of the conceptual model into a physical representation are outlined in general within this clause,
and in specific in the narrative in Clause 6Clause 6.
5.2 Directionality and indirection of relationships
In ISO/IEC 11179-3:2013, relationship directionality and end point visibility are not specified, and there are
many points in the model where it is possible to create content that indirectly references itself either
immediately or as part of larger cyclic structures. While direct implementation of such models is possible in
XML Schema, additional code – Schematron rules or an XForm/XQuery API – is required to ensure documents
that validate against the schema make sense. To avoid this problem, the schemas specified here assert
directionality, and implement certain important relationships as references.
ISO/IEC DISPRF 19583-26:20242026(en)
The default directionality can be generally stated as having Data Element, Value Domain, Data Element
Concept and Conceptual Domains as the base units of content and exchange, with reference relationships
between these classes. It is assumed that these items will be ‘identified items’ according to the definition of
ISO/IEC 11179-3:2013, and thus the reference is to the item identifier for that item. Within each of these units,
dependent content is represented as a hierarchy of nodes. An exception to this principle is made for value
meanings where a choice between referring to the meaning in a separate Conceptual Domain definition, or
including the meaning directly in the Value Domain is offered to implementers who have the third use case in
5.15.1.
The model additionally defines many shared classifiers including Context, Object Class, Property, and Units of
Measure. To avoid duplication of this content at every point of reference in the XML document, these are also
required to be identified items. However, for the sake of brevity these classifiers are strictly leaves, without
explicit navigability back to the related classes: for example each Data Element Concept instance that is
classified by a particular Object Class instance is not enumerated in that Object Class instance. Reverse links
can be computed using XQuery inside an XML database representation. Additionally it is possible to separately
specify Organisations, Individuals and Contacts for large exchanges of content between registries.
5.3 Schema documents
Three normative schema documents are presented in Annexes BAnnexes B, C, C and DD::
a) a) iso11179-3_common_facilities.xsd presents the types described as common facilities in
ISO/IEC 11179-3:2013. This schema document is widely applicable to standards from the 11179 and
19763 families (Annex B(Annex B)) and is declared in the ISO/IEC 11179-3 namespace.
b) b) iso11179-3_four_corners.xsd assembles the common facilities into the main content types of
an ISO/IEC 11179-3:2013 compliant registry (Annex C(Annex C)) and is declared in the ISO/IEC 11179-3
namespace.
c) c) iso11197-3_message.xsd imports the previous schema in the ISO/IEC 11179-3 namespace to
define a document structure for exchanging content between compliant registries (Annex D(Annex D),),
new message elements are declared in the ISO/IEC 19583-26 namespace.
A further, informative schema demonstrating how schemas (a) and (b) can be used to implement an XML
database is presented in Annex EAnnex E,, imported types are in the ISO/IEC 11179-3 namespace, root
elements for database content are declared in the the ISO/IEC 19583-26 namespace.
An account of differences between ISO/IEC 11179-3:2013 and the current 2023 versions is presented in
Annex AAnnex A (informative), and a list of any class or attribute names that have been added or changed in
these schemas is presented in Annex FAnnex F. .
All four schemas are available in file form for download at https://standards.iso.org/iso-iec/19583/-26/ed-
1/en
5.4 Schema style
The style of the schema is to define a large number of global type definitions at various levels of complexity
and integration and to make these specific with local element definitions that tightly specify the kinds of
elements that can be used to compose documents. As such, a Postal_Address type is defined without
presumption that a root element of type Postal_Address will actually appear as a stand-alone XML document,
it being left to the user as to how these types are presented as a collection of documents.
The schema is presented in three parts: a ‘common facilities’ schema containing global base type definitions
for use in all implementations; a ‘four corners’ schema that assembles these common facilities into a selection
© ISO/IEC 2024 2026 – All rights reserved
of types most useful for the creation of content interchange messages, and an overarching ‘message’ schema
that assembles these types into an XML document that is used to exchange content.
It is expected that the underlying implementations of ISO/IEC 11179-3 that registry users will interact with
to create content will be most often relational, with XML representations used for content exchange and RDF
representations used for computation. Therefore, these schemas do not make use of specific XML capabilities
such as ID/IDREF for the reuse of content by reference, or any of the proposed mechanisms for content
inclusion such as XInclude. XML database implementers may wish to modify elements of the schemas to utilise
such features in their implementation platform.
5.5 Schema conventions
The following conventions have been used for mapping the ISO/IEC 11179-3:2013 model elements to W3C
XML Schema.
Every model element is represented in W3C XML Schema in the namespace http://standards.iso.org/iso-
iec/11179/-3/ed-3/en/ and is abbreviated with the namespace prefix iso-11179, except for those model
elements introduced by this document, which are in the https://standards.iso.org/iso-iec/19583/-26/ed-
1/en/ namespace.
Every class of ISO/IEC 11179-3:2013 is represented by a simple or complex type. Names maintain the
capitalization and underscores as specified in the parent standard.
6 Overview of ISO/IEC 11179-3:2013 Representation in XML Schema
6.1 General
ISO/IEC 11179-3:2013 specifies ‘item types’ such that later classes can be typed by one or more of these types.
Each of these item types is rendered as an xsd:group since W3C XML Schema does not support multiple
inheritance. e.g. Identified_Item; Designatable_Item.
Certain relationships between classes have been replaced by reference to their scoped identifier rather than
by inclusion of content, e.g. Namespace from Scoped_Identifier, designation_context from Designation.
6.2 Basic Types metamodel region (ISO/IEC 11179-3:2013, 6.2)
Basic types defined in ISO/IEC 11179-3:2013 are declared as simple types, indirected from the corresponding
XML base datatypes. It is expected that the base datatypes will function correctly in interchange and database
use cases, but indirection allows users of the schema components to further restrict the base types if required,
such as disallowing symbols in a datatype expected to hold a filename.
6.3 Basic Classes metamodel region (ISO/IEC 11179-3:2013, 6.3)
Basic classes are faithfully represented from the standard.
6.4 Identification metamodel region (ISO/IEC 11179-3:2013, 7.2)
It is at this point that the model in ISO/IEC 11179-3:2013 becomes more conceptual with the implementer
invited to decide what items to identify, name and define, together with some structures that have the
potential to be recursive. This implementation has made the following assumptions:
— — Namespaces are required to be identified and referenced by identifier when used. To avoid the
recursive relationship, attributes for identifier and version have been directly included in the type.
ISO/IEC DISPRF 19583-26:20242026(en)
— — Scoped identifiers exist as part of an identified item that refers to their namespace by reference, rather
than existing within a namespace node, as implied by a simple reading of the class diagram.
Identified_Item is rendered from the standard as a schema group for inclusion in later classes. It is assumed
in this schema that Scoped_Identifier will not exist separately of an Identified_Item.
6.5 Designation and Definition metamodel region (ISO/IEC 11179-3:2013, Clause 7)
This implementation has made the following assumptions:
— — Naming Conventions are identified items, instances are referenced by their scoped identifiers.
— — Context is set to be both an identified item and a designatable item. The recursive relationships to
designation and definition contexts have been removed by localising appropriate attributes from the
definition and designation classes within the Context type.
— — Relationships between designations have been supported in the following way: it is possible to include
a specific definition local to a designation, and a designation may be listed as a designation_heading,
assuming that the specific definition only has context alongside its designation, and that designations are
unique.
6.6 Registration metamodel region (ISO/IEC 11179-3:2013, Clause 8)
Implementation of the registration and administration classes is mostly as described in the standard except
for the implementation of relationships between registered item, administered item and attached item. The
combination of the inheritance relationship between registered, administered and attached item and the
composition relationship between administered and attached item creates errors in later parts of the schema
if both the administered and attached item types contain registered item attributes. Implementation of the
inheritance relationship is deferred until the introduction of the ‘Metadata_Item’ type to encapsulate the
notions of identification, naming, classification, registration, administration and attachment.
6.7 Concepts package (ISO/IEC 11179-3:2013, Clause 9), Binary Relations package (ISO/IEC
11179-3:2013, Clause 10)
As modelled, the concepts and binary relations packages contain the greatest scope for recursion and
repetition of content when implementing the conceptual model as a hierarchical structure. Since it is best
practice for every concept in a concept system to be explicitly identified and named, this implementation has
taken the opportunity to replace many of the relationships between classes in this part of the model with
scoped identifier references, with attributes at both endpoints of the relationship.
It is also best practice to administer/publish a concept system as a complete entity, rather than in pieces. Thus
administration and attachment are reserved for the Concept_System type, rather than being applied to its
components.
6.8 Metadata Item Type
The overall approach of the modelling in ISO/IEC 11179-3:2013 is to define a number of conceptual ‘types’
that may be applied to content classes. Thus identification, classification, designation, registration,
administration and attachment all have associated types that are applied by the implementer according to the
policies specified by the registrar. This allows the standard to support a wide variety of registries from those
that create and maintain content in detail to ones that aggregate content that is registered elsewhere.
W3C XML schema does not support multiple inheritance. The approach taken has been to declare an abstract
class of ‘Metadata_Item’ – which can optionally be identified, named, classified, registered and either
administered or attached – and for the classes in the data description class to inherit from this. This simplifies
© ISO/IEC 2024 2026 – All rights reserved
the definition of types in the data description package, and provides a basis for further work developing
schemas for other parts of ISO/IEC 11179 together with the ISO/IEC 19763 family that share these notions.
6.9 Data Description package (ISO/IEC 11179-3:2013, Clause 11)
6.9.1 General
The approach taken to the data description package is to broadly support content kinds according to the ‘four
corners’ high level conceptual model for the data description package (ISO/IEC 11179-3:2013, Figure 11) – a
complex type is defined for each concrete class at the four corners. Implementers of XML databases can find
this causes performance issues with enumerated conceptual and value domains and may wish to factorize
these classes differently.
One issue with an XML schema implementation of the data description package is in the choice of class to
inherit from. Object Class, Property, Data Element Concept, Conceptual Domain and Value Meaning are all
kinds of Concept, but unlike concepts in a concept system – which are administered as a system – they often
require individual administration. This implementation treats these objects as being distinct from any general
concept system – i.e. either designatable or metadata items – with an additional, optional relationship to a
concept in a concept system. This is semantically safest – an assertion of association from one of these objects
to a concept cannot dislocate the target concept from its proper place in the concept system, whereas stating
equivalence between – say – a value meaning and a concept introduces to the concept system associations
with the other value meanings and the containing conceptual domain that risks changing the concept’s
meaning.
6.9.2 Measurement metamodel region (ISO/IEC 11179-3:2013, 11.4)
Since value domains measured with comparable/convertible units will usually fall naturally into the same
conceptual domain, a registry may simply maintain a flat list of units of measure and exchange these as
required when they exchange value domains. If more order is desired, since conceptually different units of
measure may share the same dimension (e.g. frequency, angular velocity), Measure_Class is the natural
containing class of this region, the compromise being that this prevents units of measure belonging to more
than one measure class.
6.9.3 Data Element Concept metamodel region (ISO/IEC 11179-3:2013, 11.2)
Data element concepts, object classes and properties are all set to be kinds of Metadata_Item, with an
additional concept reference to represent the assertion of association/equivalence with a concept in a
registered concept system.
6.9.4 Conceptual and Value Domain metamodel region (ISO/IEC 11179-3:2013, 11.3)
Conceptual and Value Domains are set to be kinds of Metadata_Item, with an additional concept reference to
represent the assertion of association/equivalence with a concept in a registered concept system. Value
Meanings include groups for identification and designation, and additionally also have a concept reference. It
is assumed that the set of Value Meanings are part of the Conceptual Domain and thus share their
administration record, the same assumption applies to Permissible Values and Value Domains. However, the
option is available to exchange meanings within a Value Domain where Conceptual Domains are unavailable.
6.9.5 Data_Element metamodel region (ISO/IEC 11179-3:2013, 11.5)
Data Elements, their derivations, and derivation rules themselves each are set to be Metadata Items with their
own administration records.
ISO/IEC DISPRF 19583-26:20242026(en)
6.10 ISO/IEC 11179-3:2013 Message and Database Schema
Finally, the types defined in 6.9 are brought together into a ‘metadata bundle’, a simple sequence of nodes of
the main content kinds in an ISO/IEC 11179-3:2013 registry, together with the registry specification and the
date and time of export (see Annex CAnnex C).). An example database schema is also offered in
Annex DAnnex D,, although it is anticipated that the basic components of ISO/IEC 11179-3:2013, and the
schema elements suggested here, could be brought together in many different ways.
© ISO/IEC 2024 2026 – All rights reserved
Annex A
(informative)
Summary of differences between ISO/IEC 11179-3:2013 and ISO/IEC 11179-
3:2023, ISO/IEC 11179-31:2023 and ISO/IEC 11179-32:2023
A.1 Overview
This document is targeted at ISO/IEC 11179-3:2013, which has been superseded by ISO/IEC 11179-3:2023
and other parts of the ISO/IEC 11179 series, such as ISO/IEC 11179-31:2023 and ISO/IEC 11179-32:2023.
This annex provides an overview of the differences.
A.2 Modularization of ISO/IEC 11179-3:2013
In the 2023 edition, ISO/IEC 11179-3:2013 has been split into multiple parts to make it more manageable. The
following are the new parts:
— — ISO/IEC 11179-30 Basic attributes of metadata;
— — ISO/IEC 11179-31 Metamodel for data specification registration;
— — ISO/IEC 11179-32 Metamodel for concept system registration.
A.3 Simplification of the UML metamodel
Some changes were made in the 2023 edition to simplify the UML model:
— — elimination of the use of UML stereotypes;
— — addition of an explicit 'Item' class as the superclass of all types of registry items;
— — removal of role names on associations;
— — removal of redundant specification of attributes and associations in the text.
A.4 Refactoring of some of the packages to reduce dependencies
Some changes were made in the 2023 edition to reduce dependencies among packages:
— — moving the Concept class to the Basic and Core package where it is referenced from multiple
metamodel regions, including: the Data Specification package in ISO/IEC 11179-31, the Concept System
package in ISO/IEC 11179-32, the Data Set package in ISO/IEC 11179-33 and the Model package in
ISO/IEC 11179-35;
— — moving the Context class to the Basic and Core package where it is referenced from the Designation
and Definition package in ISO/IEC 11179-3:2023, the Data Specification package in ISO/IEC 11179-31 and
the Data Set package in ISO/IEC 11179-33;
— — moving the Slot class to the Basic and Core package, a more appropriate location than the Identification
package;
ISO/IEC DISPRF 19583-26:20242026(en)
— — restoring a Classification region, based on the style of ISO/IEC 11179-3:2003, to remove dependency
on the Concept System region for classification.
A.5 Use of UML stereotypes in ISO/IEC 11179-3:2013
UML stereotypes were used in ISO/IEC 11179-3:2013. Each of these types (except Registered_Item which is
abstract and cannot be instantiated) can be applied to any of the instances of metadata items in the registry.
In ISO/IEC 11179-3:2023, the use of stereotypes has been replaced by subclassing from the superclass Item,
which is specified in the new Core metamodel region and which did not exist in the 2013 edition.
A.6 Differences in the Identification metamodel region
In the 2013 edition, Identified_Item is a <> which needs to be applied to instances of metadata items
that are to be identified. In the 2023 edition, Identified_Item is a regular class related to Item by the
item_identification association.
Also, Slot in the 2013 edition is related to Identified_Item, whereas in the 2023 edition it is related to Item
in the Core metamodel region.
A.7 Differences in the Designation and Definition metamodel region
In the 2013 edition, Designatable_Item is <> which needs to be applied to instances of metadata items
that are to be designated or defined;
In the 2023 edition, Designatable_Item is replaced by Item, which can be directly related to the Designation
and Definition classes;
In the 2013 edition, designation_definition_pairing is a simple association between Designation and
Definition. In the 2023 edition, Designation_Definition_Pairing is an association class, which is also
associated with Context, and has an attribute acceptability.
A.8 Differences in the Registration metamodel region
In the 2013 edition, Administered_Item and Attached_Item are <> which need to be applied to
instances of metadata items that are to be administered or attached. In the 2023 edition, Administered_Item
and Attached_Item are regular classes which are associated with Item through the item_identification
association of the grandparent class Identified_Item;
In the 2013 edition, Registration is an association class, with a registration_state attribute, and an
Administered_Item can be associated with multiple Registration_Authorities;
In the 2023 edition, registration is a simple association with a single Registration_Authority and
registration_state has been moved to Administered_Item.
In the 2023 edition, there are several differences in the Registry_Specification class:
— — the attributes standard and conformance_level have been made optional;
— — the attribute primary_language has been renamed default_language and zero, one or more
alternative_languages can be specified;
— — reference_document_identifier_form has been renamed reference_document_identifier_kind;
© ISO/IEC 2024 2026 – All rights reserved
— — representation_class_scheme has been replaced by representation_class_scheme_id, so that only the
identifier of the concept system is stored, rather than the concept system itself;
— — Several new attributes have been added:
— — degree_of_conformance;
— — conformance_label;
— — included_features;
— — excluded_features.
A.9 Differences in the Concepts metamodel region
The differences are minor. The 2023 edition has removed the subclassing of relation_link from
assertion_of_predicate, and has added Concept_Constraint_Set and Relation_Constraint_Set. The 2023
Concepts metamodel region is now in ISO/IEC 11179-32.
A.10 Differences in the Classification metamodel region
In the 2013 edition, Classifiable_Item is a <> that needs to be applied to any instance of a metadata
item that is to be classified, and the classifier is a Concept within a Concept_System. In the 2023 edition, an
Item can be classified by the association item_classification with Classification_Scheme_Item, which can be
either
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