ISO/IEC 29500-2:2021

INTERNATIONAL ISO/IEC
STANDARD 29500-2
Fourth edition
2021-08
Document description and processing
languages — Office Open XML file
formats —
Part 2:
Open packaging conventions
Description des documents et langages de traitement — Formats de
fichier "Office Open XML" —
Partie 2: Conventions de paquetage ouvert
Reference number
ISO/IEC 29500-2:2021(E)
©
ISO/IEC 2021

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ISO/IEC 29500-2:2021(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO/IEC 2021
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
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Published in Switzerland
ii © ISO/IEC 2021 – All rights reserved

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ISO/IEC 29500-2:2021(E)

Contents Page
Foreword .v
Introduction .vii
1 Scope . 1
2  Normative references . 1
3  Terms and definitions . 2
3.1 Basics . 2
3.2 Abstract package model . 3
3.3 Physical package model. 4
3.4 Digital signature and thumbnail . 5
3.5 Implementations . 5
3.6 Core properties . 5
4 Conformance . 5
5 Overview . 5
6 Abstract package model . 6
6.1 General . 6
6.2 Parts . 6
6.2.1 General. 6
6.2.2 Part names . . . 6
6.2.3 Media types . 8
6.2.4 Growth hint. 8
6.2.5 XML usage . 8
6.3 Part addressing . 8
6.3.1 General. 8
6.3.2 Pack scheme . 9
6.3.3 Resolving a pack IRI to a resource .10
6.3.4 Composing a pack IRI .10
6.3.5 Equivalence.11
6.4 Resolving relative references .11
6.4.1 General.11
6.4.2 Base IRIs .11
6.4.3 Examples .12
6.5 Relationships .14
6.5.1 General.14
6.5.2 Relationships part .14
6.5.3 Relationship markup .15
6.5.4 Examples .17
7 Physical package model .19
7.1 General .19
7.2 Physical mapping guidelines .19
7.2.1 Using features of physical formats .19
7.2.2 Mapped components .20
7.2.3 Mapping media types to parts .20
7.2.4 Interleaving .23
7.2.5 Mapping part names to physical package item names.23
7.3 Mapping to a ZIP file .25
7.3.1 General.25
7.3.2 Mapping part data .25
7.3.3 ZIP item names .26
7.3.4 Mapping logical item names to ZIP item names .26
7.3.5 Mapping ZIP item names to logical item names .26
7.3.6 ZIP package limitations .26
7.3.7 Mapping the Media Types stream .27
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ISO/IEC 29500-2:2021(E)

7.3.8 Mapping the growth hint .27
8 Core properties .27
8.1 General .27
8.2 Core Properties part .28
8.3 Core properties markup .28
8.3.1 General.28
8.3.2 Support for versioning and extensibility .29
8.3.3 coreProperties element .29
8.3.4 Core property elements .29
9 Thumbnails .32
10 Digital signatures .32
10.1 General .32
10.2 Overview of OPC-specific restrictions and extensions to “XML-Signature Syntax
and Processing” .32
10.3 Choosing content to sign .32
10.4 Digital signature parts .33
10.4.1 General.33
10.4.2 Digital Signature Origin part .33
10.4.3 Digital Signature XML Signature part .33
10.4.4 Digital Signature Certificate part .34
10.5 Digital signature markup .34
10.5.1 General.34
10.5.2 Support for versioning and extensibility .34
10.5.3 Signature element . .34
10.5.4 SignedInfo element .35
10.5.5 CanonicalizationMethod element.35
10.5.6 SignatureMethod element .35
10.5.7 Reference element . .35
10.5.8 Transform element . .36
10.5.9 RelationshipReference element .37
10.5.10 RelationshipsGroupReference element .37
10.5.11 DigestMethod element .37
10.5.12 Object element .38
10.5.13 Manifest element .38
10.5.14 SignatureProperty element .38
10.5.15 SignatureTime element .38
10.5.16 Format element .38
10.5.17 Value element .39
10.5.18 XPath element .39
10.6 Relationships transform algorithm .39
10.7 Digital signature example .40
10.8 Generating signatures .41
10.9 Validating signatures .43
Annex A (informative) Preprocessing for generating relative references .45
Annex B (normative) Constraints and clarifications on the use of ZIP features .46
Annex C (normative) Schemas - W3C XML .55
Annex D (informative) Schemas - RELAX NG .56
Annex E (normative) Standard namespaces and media types .57
Annex F (informative) Physical package model design considerations .58
Annex G (informative) Differences between ISO/IEC 29500-2 and ECMA  -376: 2006.62
Annex H (informative) Package example .63
Bibliography .65
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ISO/IEC 29500-2:2021(E)

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).
Attention is drawn to the possibility that some of the elements of this document may be the subject
of patent rights. ISO and IEC 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) or the IEC
list of patent declarations received (see patents.iec.ch).
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 JTC 1, Information technology,
Subcommittee SC 34, Document description and processing languages.
This fourth edition cancels and replaces the third edition (ISO/IEC 29500-2:2012), which has been
technically revised.
The main changes compared to the previous edition are as follows:
— Where appropriate, normative references have been updated to use undated or more recent versions
of other standards.
— Clause 3 (Terms and definitions) has been revised by removing terms not used by any normative
clauses and then reorganizing terms into groups.
— The subclause for diagram notes (5.1 in the preceding editions) has been removed, since core
properties are now defined by prose and schemas rather than by diagrams.
— The clause for acronyms and abbreviations (Clause 6 in the preceding editions) has been removed,
since it does not make sense for an ISO/IEC standard to define "ISO" and "IEC".
— Clause 6 (Abstract package model, Clause 8 in the previous edition) has been completely rewritten.
In particular, (1) pack IRIs have been defined in this clause rather than in an annex, (2) a new
subclause, "Resolving relative references", has been added; (3) part Relationships parts and
package Relationships parts have been distinguished; (4) base IRIs have been clearly defined; and
(5) handling of non-ASCII characters in part names has been clarified on the basis of RFC 3987.
— The option for media type to be an empty string has been removed, as this conflicts with the
definition of media type in RFC 2046 and the existing regular expression defined in the schema
referenced by C.2.
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ISO/IEC 29500-2:2021(E)

— Clause 7 (Physical package model, Clause 9 in the previous edition) has been slightly revised.
Interleaving has been introduced before logical item names. Percent-encoding and un-percent
encoding of non-ASCII characters have been explicitly introduced in 7.3.4 and 7.3.5.
— Clause 8 (Core properties, Clause 10 in the previous edition) has been rewritten by using prose and
schemas rather than diagrams.
— Clause 10 (Digital signatures, Clause 12 in the previous edition) has been thoroughly revised. In
particular, this clause now makes clear a convention for the choice of algorithms for signature and
digest methods, which reflects the ongoing development of algorithms since the first edition of this
document.
— Annex A has been made informative.
— The normative annex that defined pack IRIs (Annex B in the preceding editions) has been dropped.
Pack IRIs are now defined in Clause 6.
— Annex C and Annex D (Annexes D and E in the preceding editions) no longer define schemas but
reference externally defined schemas.
— Guidelines for meeting conformance requirements (Annex H in the preceding editions) have been
dropped.
— Requirements around streaming consumption have been dropped.
— Wherever possible, requirements on programs have been rewritten as those on data.
— Annex H has been added to depict an example package.
— The Index (Annex J in the preceding editions) has been deleted.
— Bibliography has been added.
A list of all parts in the ISO/IEC 29500 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 29500-2:2021(E)

Introduction
ISO/IEC 29500 (all Parts) specifies a family of XML schemas, collectively called Office Open XML, which
define the XML vocabularies for word-processing, spreadsheet, and presentation documents, as well as
the packaging of documents that conform to these schemas.
The goal is to enable the implementation of the Office Open XML formats by the widest set of tools
and platforms, fostering interoperability across office productivity applications and line-of-business
systems, as well as to support and strengthen document archival and preservation, all in a way that is
1)
fully compatible with the existing corpus of Microsoft® Office documents.
This document includes two annexes (Annex C and Annex D) that refer to data files provided in
electronic form.
The document representation formats defined by this document are different from the formats defined
in the corresponding Part of ECMA -376: 2006. Some of the differences are reflected in schema changes,
as shown in Annex G.
This fourth edition preserves all previous functionality and adds no new functionality.
1) This information is given for the convenience of users of this document and does not constitute an endorsement
by ISO or IEC of the product named. Equivalent products may be used if they can be shown to lead to the same
results.
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INTERNATIONAL STANDARD ISO/IEC 29500-2:2021(E)
Document description and processing languages — Office
Open XML file formats —
Part 2:
Open packaging conventions
1 Scope
This document defines a set of conventions for packaging one or more interrelated byte streams
(parts) as a single resource (package). These conventions are applicable not only to Office Open
XML specifications as described in ISO/IEC 29500-1 and ISO/IEC 29500-4, but also to other markup
specifications.
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.
ANSI/INCITS 4-1986 [R2017] - Information Systems - Coded Character Sets - 7-Bit American National
Standard Code For Information Interchange (7-Bit ASCII), American National Standards Institute (ANSI).
2017
FIPS 186-4, Digital Signature Standard (DSS), National Institute of Standards and Technology, US
Department of Commerce, July 2013
ISO/IEC 29500-3, Information technology — Document description and processing languages — Office
Open XML File Formats — Part 3: Markup Compatibility and Extensibility
ISO/IEC 9594-8/ITU-T Rec. X.509, Information technology — Open systems interconnection — Part 8: The
Directory: Public-key and attribute certificate frameworks
ISO 15836-1, Information and documentation — The Dublin Core metadata element set — Part 1: Core
elements
ISO 15836-2, Information and documentation — The Dublin Core metadata element set — Part 2: DCMI
Properties and classes
RFC 2046, Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types, The Internet Society,
November 1996, N. Freed and N. Borenstein. Available at https:// www .rfc -editor .org/ info/ rfc2046
RFC 3986, Uniform Resource Identifier (URI): Generic Syntax, The Internet Society, January 2005, Berners-
Lee, T., R. Fielding, and L. Masinter. Available at https:// www .rfc -editor .org/ info/ rfc3986
RFC 3987, Internationalized Resource Identifiers (IRIs), The Internet Society, January 2005, Duerst, M.
and M. Suigna
...