SIST EN ISO 21597-1:2020

SLOVENSKI STANDARD
01-julij-2020
Informacijski vsebnik za izročitev povezanih dokumentov - Specifikacija za
izmenjavo - 1. del: Vsebnik (ISO 21597-1:2020)
Information container for linked document delivery - Exchange specification - Part 1:
Container (ISO 21597-1:2020)
Informationscontainer zur Datenübergabe - Austausch-Spezifikation - Teil 1: Container
(ISO 21597-1:2020)
Conteneur d'informations pour la livraison de documents liés - Spécification d'échange -
Partie 1: Conteneur (ISO 21597-1:2020)
Ta slovenski standard je istoveten z: EN ISO 21597-1:2020
ICS:
35.240.67 Uporabniške rešitve IT v IT applications in building
gradbeništvu and construction industry
91.010.01 Gradbeništvo na splošno Construction industry in
general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 21597-1
EUROPEAN STANDARD
NORME EUROPÉENNE
April 2020
EUROPÄISCHE NORM
ICS 35.240.67; 91.010.01
English Version
Information container for linked document delivery -
Exchange specification - Part 1: Container (ISO 21597-
1:2020)
Conteneur d'informations pour la livraison de Informationscontainer zur Datenübergabe - Austausch-
documents liés - Spécification d'échange - Partie 1: Spezifikation - Teil 1: Container (ISO 21597-1:2020)
Conteneur (ISO 21597-1:2020)
This European Standard was approved by CEN on 20 April 2020.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2020 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 21597-1:2020 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 21597-1:2020) has been prepared by Technical Committee ISO/TC 59
"Buildings and civil engineering works" in collaboration with Technical Committee CEN/TC 442
“Building Information Modelling (BIM)” the secretariat of which is held by SN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by October 2020, and conflicting national standards shall
be withdrawn at the latest by October 2020.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the
United Kingdom.
Endorsement notice
The text of ISO 21597-1:2020 has been approved by CEN as EN ISO 21597-1:2020 without any
modification.
INTERNATIONAL ISO
STANDARD 21597-1
First edition
2020-04
Information container for linked
document delivery — Exchange
specification —
Part 1:
Container
Conteneur d'informations pour la livraison de documents liés —
Spécification d'échange —
Partie 1: Conteneur
Reference number
ISO 21597-1:2020(E)
©
ISO 2020
ISO 21597-1:2020(E)
© ISO 2020
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: +41 22 749 01 11
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved

ISO 21597-1:2020(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3  Terms, definitions and abbreviated terms . 2
3.1 Terms and definitions . 2
3.2 Abbreviated Terms . 5
4  Specifications . 5
4.1 Use of RDF, RDFS and OWL constructs. 5
4.2 Symbols and notations . 7
4.3 Container structure .10
4.3.1 Overview .10
4.3.2 “Ontology resources” folder .11
4.3.3 “Payload documents” folder .11
4.3.4 “Payload triples” folder .11
4.4 Ontologies and datasets .12
4.4.1 Overview .12
4.4.2 Container ontology .12
4.4.3 Linkset ontology .16
4.4.4 Index dataset .20
4.4.5 Link dataset .20
4.5 Versioning.20
4.6 Additional properties in datasets .22
5 Conformance requirements .22
Annex A (informative) Use cases.24
Annex B (informative) Dublin Core interoperability .35
Annex C (informative) Bidirectional conversion of the ICDD container representation from
RDF(S)/OWL to XSD/XML .36
Annex D (informative) How to validate with SHACL .37
Annex E (normative) Ontologies .40
Bibliography .41
ISO 21597-1:2020(E)
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 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.
This document was prepared by Technical Committee ISO/TC 59, Buildings and civil engineering works,
Subcommittee SC 13, Organization and digitization of information about buildings and civil engineering
works, including building information modelling (BIM), in collaboration with the European Committee
for Standardization (CEN) Technical Committee CEN/TC 442, Building Information Modelling (BIM), in
accordance with the Agreement on technical cooperation between ISO and CEN (Vienna Agreement).
A list of all parts in the ISO 21597 series can be found on the ISO website.
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.
iv © ISO 2020 – All rights reserved

ISO 21597-1:2020(E)
Introduction
The ISO 21597 series has been developed in response to a recognized need within the construction
industry to be able to handle multiple documents as one information delivery.
Information deliveries are often a combination of drawings, information models (representing built
or natural assets in the physical world), text documents, spreadsheets, photos, videos, audiofiles, etc.
Increasingly, this may also include datasets based on any ontology. An ability to specify relationships
using links between information elements in those separate documents can contribute significantly
to the value of an information delivery. The composition of such a package arises both from the
requirements of the process, e.g. delivery of as-built information, and from the specific functional
purpose e.g. performing a quantity take-off or communication about issues in 3D models.
In this document a specification is given for a container that stores documents, along with a means of
linking otherwise disconnected data within those documents.
The container format includes a header file and optional link files that define relationships by including
references to the documents, or to elements within them. The header file uniquely identifies the
container and its contractual or collaborative intention. This information is defined using the RDF,
RDFS and OWL semantic web standards.
The header file, along with any additional RDF(S)/OWL files or resources, forms a suite that may be
directly queried by software. The link references may be interpreted by the recipient applications or
reviewed interactively by the recipient. Where it includes link references into the content of documents
that don’t support standardized querying mechanisms, their resolution may depend on third party
interpreters.
The format can also be used to deliver multiple versions of the same document.
INTERNATIONAL STANDARD ISO 21597-1:2020(E)
Information container for linked document delivery —
Exchange specification —
Part 1:
Container
IMPORTANT — The electronic file of this document contains colours which are considered to be
useful for the correct understanding of the document. Users should therefore consider printing
this document using a colour printer.
1 Scope
This document defines an open and stable container format to exchange files of a heterogeneous nature
to deliver, store and archive documents that describe an asset throughout its entire lifecycle.
It is suitable for all parties dealing with information concerning the built environment, where there is
a need to exchange multiple documents and their interrelationships, either as part of the process or
as contracted deliverables. The format is intended to use resources either included in the container
(such as documents) or referenced remotely (such as web resources). A key feature is that the container
can include information about the relationships between the documents. Relevant use-cases reflect the
need for information exchange during the entire life cycle of any built asset and can include, but are not
limited to, the handover of
1. a published bidding package,
2. required project deliverables at a specific project stage (e.g. when proposing different design
scenarios),
3. shared information as background or for further development,
4. published approval packages, or
5. information about versions between partners to provide a means to reference particular states of
the information and track changes.
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 21320-1, Information technology — Document Container File — Part 1: Core.
IANA. Internet Assigned Numbers Authority Media Types. [viewed 6 May 2019]. Available from:
https:// www .iana .org/ assignments/ media -types/ media -types .xhtml
W3C-OWL2-SPEC. Motik B., Patel-Schneider P.F., Parsia B. eds. OWL 2 Web Ontology Language:
Structural Specification and Functional-Style Syntax (Second Edition). W3C Recommendation, 11
December 2012 [viewed July 22nd 2019]. Latest version available at http:// www .w3 .org/ TR/ owl2
-syntax/
W3C-RDF11-CONCEPTS. Cyganiak R., Wood D., Lanthaler M. RDF 1.1 Concepts and Abstract Syntax.
W3C Recommendation, 25 February 2014 [viewed July 22nd 2019]. Latest version available at http://
www .w3 .org/ TR/ rdf11 -concepts/
ISO 21597-1:2020(E)
W3C-RDF11-SCHEMA. Brickley D., Guha R.V. RDF Schema 1.1. W3C Recommendation, 25 February
2014 [viewed July 22nd 2019]. Latest version available at http:// www .w3 .org/ TR/ rdf -schema/
W3C-RDF11-XML. Gandon F., Schreiber G. RDF 1.1 XML Syntax. W3C Recommendation, 25 February
2014 [viewed July 22nd 2019]. Latest version available at http:// www .w3 .org/ TR/ rdf -syntax -grammar/
W3C-XML-DATATYPES. Peterson D., Gao S., Malhotra A., Sperberg-McQueen C.M., Thompson
H.S. eds. (Version 1.1) and Biron P.V., Malhotra A. eds. (Version 1.0). W3C XML Schema Definition
Language (XSD) 1.1 Part 2: Datatypes. W3C Recommendation, 5 April 2012 [viewed July 22nd 2019].
Latest version available at http:// www .w3 .org/ TR/ xmlschema11 -2/
3  Terms, definitions and abbreviated terms
3.1  Terms and definitions
For the purposes of this document, the following terms and definitions 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 http:// www .electropedia .org/
3.1.1
container
file that conforms to the ISO 21597 series
3.1.2
payload
primary information in the form of documents (3.1.3) that is included within the container (3.1.1)
Note 1 to entry: This does not include the header file (Index.rdf) or the ontology (3.1.7) resource (3.1.14) files.
3.1.3
document
fixed and structured amount of information that can be managed and interchanged as a unit between
users and systems
Note 1 to entry: This unit may not necessarily be human perceptible. Information is usually stored on a data medium.
Note 2 to entry: Used in the ISO 21597 series to refer to any document that forms part of the payload (3.1.2) in the
container, including any 2D or 3D models that represent built or natural assets in the physical world; these may
be held in any standard or proprietary format.
3.1.4
internal document
document (3.1.3) located within the container (3.1.1)
3.1.5
external document
document (3.1.3) located outside the container (3.1.1)
3.1.6
link
relation between documents (3.1.3), including between elements in documents
2 © ISO 2020 – All rights reserved

ISO 21597-1:2020(E)
3.1.7
ontology
specification of concrete or abstract things, and the relationships among them, in a prescribed domain
of knowledge
Note 1 to entry: The specification should be computer processable.
Note 2 to entry: The definition is adapted from W3C-OWL2-SPEC.
3.1.8
container ontology
RDF(S)/OWL file providing the object (3.1.23) classes (3.1.15) and properties that shall be used to
specify the contents of a container (3.1.1)
3.1.9
linkset ontology
RDF(S)/OWL file providing the object (3.1.23) classes (3.1.15) and properties that shall be used to
specify links (3.1.6) between documents (3.1.3) in a container (3.1.1)
3.1.10
dataset
RDF(S)/OWL file that contains individuals (3.1.16) that comply with the classes (3.1.15) as specified by
ontologies (3.1.7)
3.1.11
index dataset
RDF(S)/OWL file containing an index of the contents of the container (3.1.1)
3.1.12
link dataset
RDF(S)/OWL file containing links (3.1.6) as defined in the ISO 21597 series
3.1.13
serialisation
encoding of an ontology (3.1.7) or dataset (3.1.10) into a format that can be stored, typically in a file
Note 1 to entry: The definition is adapted from W3C-RDF11-XML.
3.1.14
resource
something in the world (the "universe of discourse") denoted by an IRI or literal
Note 1 to entry: Anything can be a resource, including physical things, documents (3.1.3), abstract concepts,
numbers and strings; the term is synonymous with "entity" as it is used in the RDF Semantics specification.
Note 2 to entry: The definition is adapted from W3C-RDF11-CONCEPTS.
3.1.15
class
set of individuals (3.1.16) having the same characteristics
Note 1 to entry: The definition is adapted from W3C-RDF11-SCHEMA, 2.2.
3.1.16
individual
resource (3.1.14) that has been placed into any RDFS class (3.1.15) as an instance of that class
Note 1 to entry: Like RDF classes, every OWL class is associated with a set of individuals, called the class
extension; the individuals in the class extension are the instances of the class.
Note 2 to entry: There are two types of individuals in the syntax of OWL 2. Named individuals are given an
explicit name that can be used in any ontology (3.1.7) to refer to the same object (3.1.23). Anonymous individuals
do not have a global name and are thus local to the ontology in which they are contained.
ISO 21597-1:2020(E)
Note 3 to entry: The definition is adapted from W3C-OWL2-SPEC, 5.6.
3.1.17
object property
OWL property that links individuals (3.1.16) to other individuals
Note 1 to entry: The definition is adapted from W3C-OWL2-SPEC, 5.3.
3.1.18
datatype property
OWL property that can relate individuals (3.1.16) to literals
Note 1 to entry: Literals can be strings, numbers, date types, etc.
Note 2 to entry: The definition is adapted from W3C-OWL2-SPEC, 5.4.
3.1.19
namespace
group of identifiers for elements and attributes that are collectively bound to a URI such that their use
will not cause naming conflicts
Note 1 to entry: The definition is adapted from W3C-RDF11-CONCEPTS, 1.
3.1.20
triple
statement in the form subject-predicate-object (3.1.21, 3.1.22, 3.1.23) that expresses a relationship
between two resources (3.1.14)
Note 1 to entry: The definition is adapted from W3C-RDF11-CONCEPTS, 3.1.
3.1.21
subject
resource (3.1.14) (an IRI) about which a statement is made in the form of an RDF triple (3.1.20)
Note 1 to entry: This term, as used in the ISO 21597 series, is part of the RDF(S)/OWL vocabulary, where each
triple consists of a subject, a predicate (3.1.22) and an object (3.1.23); a set of such triples is called an RDF graph.
Note 2 to entry: The definition is adapted from W3C-RDF11-SCHEMA, 5.3.2.
3.1.22
predicate
the relationship between a subject (3.1.21) and an object (3.1.23) in an RDF triple (3.1.20), also called a
property
Note 1 to entry: The definition is adapted from W3C-RDF11-SCHEMA, 5.3.3.
3.1.23
object
resource (3.1.14) (either an IRI or a literal) assigned as the specified property of the subject (3.1.21) in a
triple (3.1.20)
Note 1 to entry: This term, as used in the ISO 21597 series, is part of the RDF(S)/OWL vocabulary, where each
triple consists of a subject, a predicate (3.1.22) and an object; a set of such triples is called an RDF graph.
Note 2 to entry: The definition is adapted from W3C-RDF11-SCHEMA, 5.3.4.
4 © ISO 2020 – All rights reserved

ISO 21597-1:2020(E)
3.2  Abbreviated Terms
DBF DataBase File
GIS Geographic Information System
GML Geography Markup Language
GUID Globally Unique Identifier
ICDD Information Container for linked Document delivery
IFC Industry Foundation Classes
IRI Internationalized Resource Identifier
OWL Web Ontology Language
RDF Resource Description Framework
RDFS Resource Description Framework Schema
SHACL Shapes Constraint Language
SPARQL Simple Protocol And RDF Query Language
SQL Structured Query Language
UML Unified Modeling Language
URI Uniform Resource Identifier
URL Uniform Resource Locator
W3C World Wide Web Consortium
XML eXtensible Markup Language
XSD XML Schema Definition
XSLT Extensible Stylesheet Language Transformations
NOTE IRI is an update of the URI released in 2005; while URIs are limited to a subset of the ASCII character set,
IRIs can contain characters from the Universal Character Set (Unicode/ISO/IEC 10646). In the ISO 21597 series
URIs and IRIs are used interchangeably.
4  Specifications
4.1 Use of RDF, RDFS and OWL constructs
All ontologies held in containers that conform to the ISO 21597 series shall be based on the languages
RDF [W3C-RDF11-CONCEPTS], RDFS [W3C-RDF11-SCHEMA] and OWL [W3C-OWL2-SPEC] (referred to
collectively in the ISO 21597 series as RDF(S)/OWL) and shall be serialized in RDF/XML [W3C-RDF11-
XML] or any other equivalent RDF serialisation recommended by W3C.
It is expected that RDF(S)/OWL will be an important technology and a general platform for ontologies
for the coming decades. Proprietary systems will increasingly adopt RDF(S)/OWL. However, to make
the threshold for adoption of this document as low as possible, Annex C provides specifications to
support the conversion of a container from RDF(S)/OWL to XSD/XML and vice versa.
ISO 21597-1:2020(E)
In general, when used in the context of the world wide web, these languages use the following principles
to support reasoning:
— Open world assumption - the truth of a statement is independent of whether it is known. In other
words, not knowing that a statement is explicitly true does not imply that the statement is false.
— No unique names assumption - unless explicitly stated otherwise, it cannot be assumed that
resources that are identified by different URIs are different.
The datasets that comply with the ontologies specified in the ISO 21597 series shall use the following
interpretation of RDF(S)/OWL:
— Closed world assumption - a statement that is true is also known to be true; therefore, conversely,
what is not formally specified in a container to be true, is false.
— Unique naming assumption - resources in a container that are identified with different URIs are
considered to be different, unless explicitly declared as the same (using the owl: sameAs predicate).
Table 1 lists the RDF(S)/OWL constructs that are used in the ISO 21597 series and the interpretation to
be used when validating the contents of a container. It is noted that, once the contents of the container
has been validated, the data can be used in an open world context.
Table 1 — Listing of constructs used in the ISO 21597 series and their interpretation
Construct Interpretation
owl: Class In a dataset within a container, class membership
for every individual shall be explicitly asserted,
unless implicitly inferred using predicates such
as rdfs:s ubClassOf [W3C-RDF11-SCHEMA, 3.4]
or owl: equivalentClass [W3C-OWL2-SPEC, 9.1.2].
rdfs: subClassOf The ISO 21597 series does not deviate from the W3C
definitions [W3C-RDF11-SCHEMA]. Statements that
rdfs: subPropertyOf
may be inferred due to
rdfs: subClassOf or rdfs: subPropertyOf statements shall
be regarded as true even if not explicitly asserted.
NOTE  Statements where a class is mentioned are also
true for any of its subclasses. Similarly, statements
where a property is mentioned are also true for any of
its sub properties.
owl: FunctionalProperty The ISO 21597 series interprets
owl: FunctionalProperty as a property with a
maximum cardinality of 1.
[W3C-OWL2-SPEC, 9.2.4]
owl: InverseFunctionalProperty The ISO 21597 series interprets
owl: InverseFunctionalProperty as an inverse
property with a maximum cardinality of 1.
[W3C-OWL2-SPEC, 9.2.7]
owl: equivalentClass The ISO 21597 series does not deviate from the W3C
definitions [W3C-OWL2-SPEC, 9.1.2]. Statements that
may be inferred due to owl: equivalentClass
statements shall be regarded as true even if not
explicitly asserted.
rdfs: range These statements shall be interpreted as restrictions.
It is invalid to have a subject or object of a statement
r df s: domain
(triple) in a dataset where that individual is a member
of a class that does not comply with the rdfs: range or
r df s: domain declarations of the corresponding
owl: ObjectProperty [W3C-OWL2-SPEC, 5.3] or
owl: DatatypeProperty [W3C-OWL2-SPEC, 5.4]
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ISO 21597-1:2020(E)
Table 1 (continued)
Construct Interpretation
owl: restriction These statements shall be interpreted as restrictions.
Any deviation from the specified restriction within a
owl: onProperty
single container is considered invalid.
owl: allValuesFrom
NOTE  As an example, if owl: cardinality is defined as 2,
owl: someValuesFrom then a dataset that does not contain exactly 2
occurrences is not valid.
owl: hasValue
owl: cardinality
owl: minCardinality
owl: maxCardinality
owl: inverseOf The ISO 21597 series does not deviate from the W3C
definitions [W3C-OWL2-SPEC, 9.2.4]. It is
recommended that inverse properties are not
asserted for individuals in a dataset. If they are
asserted, they shall not contradict the assertions
made in the opposite direction.
owl: disjointUnionOf The expression shall be interpreted as a constraint
where the subject is considered to be an abstract class
in the sense that any individual member of the subject
class shall also be a member of one (and only one) of
the disjoint classes enumerated in the object part of the
owl: disjointUnionOf statement. [W3C-OWL2-SPEC, 9.1.4]
4.2  Symbols and notations
Throughout the ISO 21597 series, the structure of the ontologies is illustrated using a UML notation.
The purpose of this subclause is to describe that notation and the meaning of the terms and symbols
that are used.
Tables 2 and 3 list the namespaces and corresponding prefixes used in the ISO 21597 series.
Table 2 — Namespaces and prefixes used in ontologies defined in the ISO 21597 series
Ontology Prefix Namespace
Container ontology ct https:// standards .iso .org/ iso/ 21597/ -1/ ed -1/ en/ Container
Linkset ontology ls https:// standards .iso .org/ iso/ 21597/ -1/ ed -1/ en/ Linkset
Table 3 — Namespaces and prefixes used in ontologies referenced in the ISO 21597 series
Ontology Prefix Namespace
XML Schema xsd https:// www .w3 .org/ 2001/ XMLSchema
Resource Description rdf
https:// www .w3 .org/ 1999/ 02/ 22 -rdf -syntax -ns
Framework
RDF Schema rdfs https:// www .w3 .org/ 2000/ 01/ rdf -schema
Web Ontology owl https:// www .w3 .org/ 2002/ 07/ owl
Language
Figure 1 illustrates the UML notations used in the ISO 21597 series to render classes and properties.
ISO 21597-1:2020(E)
Figure 1 — UML notation for classes and properties
A class (owl: Class) is illustrated by a rectangular box with two compartments as shown in Figure 1. In
the upper compartment, the class name (“ex: Class” in Figure 1) is displayed. Note that the class name
is shown following the pattern “prefix: ClassName”, where the prefix (“ex” in the example) denotes
namespace of the ontology and “ClassName” is the name of the class. The prefixes actually used in the
ISO 21597 series are defined in Tables 2 and 3.
The lower compartment shows the specified properties for that class. There are two general types of
properties:
— Datatype properties are those for which the value is a data literal, as illustrated for ex: AnotherClass
in Figure 1; and
— Object properties, for which the value is an individual; e.g. ex: Class in Figure 1, where the property
ex: ObjectProperty _1 references an individual of class ex: AnotherClass.
The property definitions are shown according to the pattern “prefix: propertyName: range[cardinality]”.
The range of a datatype property shall be based on one of the predefined data types in XML schema
[W3C-XML-DATATYPES]. The range of an object property is usually one of the classes occurring in the
ontology but may also refer to a class in another ontology.
If classes on both sides (domain and range) of an object property are visible in a diagram, the object
property may also be illustrated with an (blue) arrow between the classes pointing from the domain
class towards the range class (as shown in Figure 1). The name of the object property is displayed along
the arrow as well as in the property compartment of the class box as explained above.
Any cardinality restrictions are displayed within square brackets using the following notation:
[minCardinality.maxCardinality], where minCardinality specifies the minimum allowed occurrences and
maxCardinality specifies the maximum allowed number of occurrences
The cardinality restrictions shall be interpreted in the following fashion:
— omitted - no cardinality restriction exists, i.e. any number of occurrences from zero to many are
allowed;
— maxCardinality omitted (e.g. [0.], [1.] etc) - maximum cardinality is unrestricted.
If two classes are related using an rdfs:s ubClassOf predicate, this is rendered using an arrow as shown
in Figure 2. This diagram illustrates that ex: SubClass and ex: Class are related using an rdfs:s ubClassOf
predicate.
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ISO 21597-1:2020(E)
Figure 2 — Depiction of a sub-class relationship
Disjoint classes are illustrated in Figure 3.
Figure 3 — Depiction of disjoint classes
The red arrow pointing from ex: Class1 to ex: Class2 declares that they are disjoint, meaning that an
instance is not allowed to be a member of both ex: Class1 and ex:C lass2. This is declared with an owl:
disjointUnionOf statement (ex: Class1 owl: disjointUnionOf ex: Class2). The owl: disjointUnionOf property is
symmetric, meaning that if Class1 is disjoint with Class2, then Class2 is also disjoint with Class1.
Two classes which are declared as equivalent by the use of owl: equivalentClass (e.g. ex: Class3 owl:
equivalentClass ex: Class4) are depicted as shown in Figure 4.
Figure 4 — Depiction of equivalent classes
Finally, a class may be both the Domain and Range for a certain ObjectProperty. Such a relationship is
rendered as shown in Figure 5, i.e. with the little arrow aligned to the bottom of the class box without
any label attached to the arrow.
Figure 5 — Depiction of an ObjectProperty defined by an individual of the same class
ISO 21597-1:2020(E)
4.3 Container structure
4.3.1 Overview
A container is a file that shall have an extension “.icdd” and shall comply with ISO/IEC 21320-1 also
known as ZIP64.
A container includes a header file in the top-level folder; this file shall comply with the RDF(S)/
OWL standards and shall be serialized in RDF/XML [W3C-RDF11-XML] or any other equivalent RDF
serialisation recommended by W3C. The name of this header file is Index.rdf.
As a minimum, a container shall have at least three folders as illustrated in Figure 6. The purpose of
these top-level folders is explained in the following subclauses. The “Payload documents” folder and
“Payload triples” folder may contain nested folders to allow groups of associated digital resources to be
held together and referenced as a group (e.g. a building information model with its associated reference
files or a set of linked spreadsheets).
Figure 6 — Minimum structure of the root of a container
Figure 7 shows the hierarchy of folders and files within a container.
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ISO 21597-1:2020(E)
Figure 7 — Hierarchy of folders and files in a container
4.3.2 “Ontology resources” folder
The “Ontology resources” folder can be used to store the Linkset.rdf and Container.rdf ontologies that
together provide the object classes and properties that shall be used to specify the contents of and
links between the documents within the container. These ontologies shall be serialized in the RDF/
XML format [W3C-RDF11-XML] or any other equivalent RDF serialisation recommended by W3C. Since
they are both available as downloadable files (and therefore can be referenced as resources held locally
but external to the container), it is not mandatory to include them here, but if included, the files in this
folder shall take precedence.
4.3.3 “Payload documents” folder
The “Payload documents” folder shall be used for storing all the documents that are included in the
container (referred to as the payload). Sub-folders are allowed.
4.3.4 “Payload triples” folder
The “Payload triples” folder shall be used for storing Linkset files and may include sub-folders.
ISO 21597-1:2020(E)
4.4 Ontologies and datasets
4.4.1 Overview
Using RDF(S)/OWL technology, the object classes and properties that are used to specify the contents
of and links between the documents within the container is specified within the container using two
ontologies:
— Container ontology, available online via https:// standards. iso .org/ iso/ 21597/ -1/ ed -1/ en/
Container .rdf.
— Linkset ontology, available online via https:// standards .iso .org/ iso/ 21597/ -1/ ed -1/ en/ Linkset .rdf.
As noted previously, these ontologies can be included in the container in the “Ontology resources” folder
to create a self-contained container that may be used off-line or for archiving purposes. Since these
ontologies conform to the ISO 21597 series, they shall not be modified in any way.
In addition, the container shall include RDF(S)/OWL datasets that describe the contents of the container
and the links between those documents. We distinguish two types of datasets. First, the container shall
include one Index dataset, called Index.rdf and held in the root of the container; it is used to describe the
container and to specify the documents that make up its contents. Second, the container may include
zero or more Link datasets, used to specify the link relationships among documents. All such datasets
shall reference the Container and Linkset ontologies in Annex E.
The Container and Linkset ontologies are described in 4.4.2 and 4.4.3. The two types of dataset
described in the previous paragraph are then described in 4.4.4 and 4.4.5 respectively.
4.4.2 Container ontology
The Container ontology is an RDF(S)/OWL file containing definitions of the classes and properties used
in an Index dataset, providing metadata about the container.
The Index dataset enables the specification of:
— version of ICDD standard via the import of the reference ontology;
— list of external documents with metadata:
— mandatory file name (including a URI or IRI);
— optional format;
— optional description;
— list of internal documents with metadata:
— mandatory file name (including its path in the container folder structure);
— optional format;
— optional description;
— reference to Link datasets.
Tables 4, 5 and 6 list the objects, datatype properties and object properties respectively that are used in
the Container ontology, providing brief descriptions of each.
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ISO 21597-1:2020(E)
Table 4 — Classes defined in the Container ontology
Object name Description
ct: ContainerDescription A description for a container where all documents are listed and where Link
datasets can be found. There shall be exactly one ct: ContainerDescription
instance in any container.
ct:E ncryptedDocument A reference to an encrypted document.
ct:E xternalDocument A reference to a document outside a container.
ct:I nternalDocument A reference to a document inside a container.
ct: Linkset A reference to an RDF(S)/OWL file containing links.
ct:D ocument An abstract class for references to a document; an individual shall be a member of
ct:E xternalDocument or ct: InternalDocument; and optionally, individuals may also
be a member of other subtypes of ct: Document such as ct: SecuredDocument and/or
ct:E ncryptedDocument.
ct: SecuredDocument A document secured by a checksum algorithm (see also properties ct: checksum and
ct: checksumAlgorithm).
ct: FolderDocument A document comprising multiple files located in one folder, such as a GIS
dataset consisting SHP files with associated DBF files.
ct: Party An abstract class that represents the generalization of a ct: Organisation or a
ct: Pe r s on; entities can refer to an individual of a subclass of ct: Party via the
ct: c r e at or, ct: modifier or ct: publisher object properties.
ct: Pe r s on A class representing a person for provenance purposes.
ct: Organisation A class representing an organization for provenance purposes.
Table 5 — Datatype properties used in the Container ontology
Datatype name Description
ct: checksum A checksum hash for the document reference; the checksum algorithm
is specified by the property ct: checksumAlgorithm.
ct: checksumAlgorithm The algorithm used to generate the checksum hash.
ct: conformanceIndicator A string-based indicator
...