ISO/IEC 23736-2:2020

INTERNATIONAL ISO/IEC
STANDARD 23736-2
First edition
2020-02
Information technology — Digital
publishing — EPUB 3.0.1 —
Part 2:
Publications
Technologies de l'information — Publications numériques — EPUB
3.0.1 —
Partie 2: Publications
Reference number
©
ISO/IEC 2020
© ISO/IEC 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
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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/IEC 2020 – All rights reserved

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 (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 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 http://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.
This document was prepared by the World Wide Web Consortium (W3C) (as EPUB Publications 3.0.1)
and drafted in accordance with its editorial rules. It was adopted, under the JTC 1 PAS procedure,
by Joint Technical Committee ISO/IEC JTC 1, Information technology.
A list of all parts in the ISO/IEC 23736 series can be found on the ISO websitte.e
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.
© ISO/IEC 2020 – All rights reserved iii

EPUB Publications 3.0.1
Recommended Specification 26 June 2014
THIS VERSION
http://www.idpf.org/epub/301/spec/epub-publications-20140626.html
LATEST VERSION
http://www.idpf.org/epub3/latest/publications
PREVIOUS VERSION
http://www.idpf.org/epub/301/spec/epub-publications-20140228.html
A diff of changes from the previous version is also available.
Please refer to the errata for this document, which may include some normative corrections.
All rights reserved. This work is protected under Title 17 of the United States Code. Reproduction and
dissemination of this work with changes is prohibited except with the written permission of the International
Digital Publishing Forum (IDPF).
EPUB is a registered trademark of the International Digital Publishing Forum.
Editors
Markus Gylling, International Digital Publishing Forum (IDPF)
William McCoy, International Digital Publishing Forum (IDPF)
Matt Garrish, Invited Expert
TABLE OF CONTENTS
1. Overview
1.1. Purpose and Scope
1.2. Terminology
1.3. Typographic Conventions
1.4. Conformance Statements
2. EPUB Publications
2.1. Content Conformance
2.2. Reading System Conformance
3. Package Documents
3.1. Introduction
3.2. Content Conformance
3.3. Reading System Conformance
3.4. Package Document Definition
3.4.1. The package Element
3.4.2. The metadata Element
3.4.3. The DCMES identifier Element
3.4.4. The DCMES title Element
3.4.5. The DCMES language Element
© ISO/IEC 2020 – All rights reserved 1

ISO/IEC 23736-1:2020(E)
3.4.6. The DCMES Optional Elements
3.4.7. The meta Element
3.4.8. The meta Element (OPF2) [OBSOLETE]
3.4.9. The link Element
3.4.10. The manifest Element
3.4.11. The item Element
3.4.12. The spine Element
3.4.13. The itemref Element
3.4.14. The guide Element [DEPRECATED]
3.4.15. The bindings Element
3.4.16. The mediaType Element
3.4.17. The collection Element
4. Package Metadata
4.1. Publication Identifiers
4.1.1. Unique Identifier
4.1.2. Release Identifier
4.2. Vocabulary Association Mechanisms
4.2.1. Overview
4.2.2. Default Vocabulary
4.2.3. Reserved Prefixes
4.2.4. The prefix Attribute
4.2.5. The property Data Type
4.2.5.1. Syntax
4.2.5.2. Processing
4.3. Package Metadata Vocabulary
4.3.1. Overview
4.3.2. Metadata meta Properties
4.3.2.1. Publication
4.3.2.2. Rendering
4.3.3. Metadata link Properties
4.3.4. Manifest item Properties
4.3.5. Spine itemref Properties
4.4. Publication Rendering
4.4.1. General Properties
4.4.1.1. Overview
4.4.1.2. The rendition:flow Property
4.4.1.2.1. Usage
4.4.1.2.2. Allowed values
4.4.1.2.3. Spine Overrides
4.4.1.3. The rendition:align-x-center Property
4.4.2. Fixed-Layout Properties
4.4.2.1. Overview
4.4.2.2. The rendition:layout Property
4.4.2.2.1. Usage
4.4.2.2.2. Allowed values
4.4.2.2.3. Spine Overrides
4.4.2.3. The rendition:orientation property
4.4.2.3.1. Usage
4.4.2.3.2. Allowed values
4.4.2.3.3. Spine Overrides
4.4.2.4. The rendition:spread Property
4.4.2.4.1. Usage
4.4.2.4.2. Allowed values
4.4.2.4.3. Spine Overrides
4.4.2.5. The page-spread-* Properties
4.4.2.6. The rendition:viewport Property
5. Publication Resources
5.1. Core Media Types
5.2. Restrictions and Fallbacks
5.2.1. Foreign Resource Restrictions
5.2.2. Manifest Fallbacks
5.3. Publication Resource Locations
2 © ISO/IEC 2020 – All rights reserved

5.4. XML Conformance
A. Package Document Schema
B. The application/oebps-package+xml Media Type
C. Acknowledgements and Contributors
References
› 1 Overview
› 1.1 Purpose and Scope
This section is informative
This specification, EPUB Publications 3.0.1, defines semantics and conformance requirements for
EPUB® Publications, including the format of the Package Document that describes each Rendition of
the content and rules for how this document and other Publication Resources are associated to
create a conforming EPUB Publication.
This specification is one of a family of related specifications that compose EPUB 3, the third major
revision of an interchange and delivery format for digital publications based on XML and Web
Standards. It is meant to be read and understood in concert with the other specifications that make up
EPUB 3:
The EPUB 3 Overview [EPUB3Overview], which provides an informative overview of EPUB and
a roadmap to the rest of the EPUB 3 documents. The Overview should be read first.
EPUB Content Documents 3.0.1 [ContentDocs301], which defines profiles of XHTML, SVG and
CSS for use in the context of EPUB Publications.
EPUB Open Container Format (OCF) 3.0.1 [OCF301], which defines a file format and
processing model for encapsulating a set of related resources into a single-file (ZIP) EPUB
Container.
EPUB Media Overlays 3.0.1 [MediaOverlays301], which defines a format and a processing
model for synchronization of text and audio.
This specification supersedes EPUB Publications 3.0 [Publications30]. Refer to [EPUB3Changes] for
information on differences between this specification and its predecessor.
› 1.2 Terminology
EPUB Publication
A collection of one or more Renditions conforming to this specification and its sibling
specifications , packaged in an EPUB Container.
An EPUB Publication typically represents a single intellectual or artistic work, but this
specification and its sibling specifications do not circumscribe the nature of the content.
Rendition
© ISO/IEC 2020 – All rights reserved 3

ISO/IEC 23736-1:2020(E)
A logical document entity consisting of a set of interrelated resources representing one
rendering of an EPUB Publication.
Default Rendition
The Rendition listed in the first rootfile element in the Container – META-
INF/container.xml [OCF301] file.
Publication Resource
A resource that contains content or instructions that contribute to the logic and rendering of
at least one Rendition of an EPUB Publication. In the absence of this resource, the EPUB
Publication might not render as intended by the Author. Examples of Publication Resources
include a Rendition's Package Document, EPUB Content Document, EPUB Style Sheets,
audio, video, images, embedded fonts and scripts.
With the exception of the Package Document itself, the Publication Resources required to
render a Rendition are listed in that Rendition's manifest and bundled in the EPUB
Container file (unless specified otherwise in Publication Resource Locations).
Examples of resources that are not Publication Resources include those identified by the
Package Document link element and those identified in outbound hyperlinks that resolve
outside the EPUB Container (e.g., referenced from an [HTML5] a element href attribute).
Foreign Resource
A Publication Resource that is not a Core Media Type. A Foreign Resource requires at
least one fallback, as defined in Restrictions and Fallbacks.
Core Media Type Resource
A Publication Resource that is a Core Media Type and may therefore be included in the
EPUB Publication without the provision of fallbacks.
EPUB Content Document
A Publication Resource that conforms to one of the EPUB Content Document definitions
(XHTML or SVG).
An EPUB Content Document is a Core Media Type, and may therefore be included in the
EPUB Publication without the provision of fallbacks.
XHTML Content Document
An EPUB Content Document conforming to the profile of [HTML5] defined in XHTML
Content Documents [ContentDocs301] .
XHTML Content Documents use the XHTML syntax of [HTML5].
SVG Content Document
An EPUB Content Document conforming to the constraints expressed in SVG Content
Documents [ContentDocs301] .
EPUB Navigation Document
A specialization of the XHTML Content Document, containing human- and machine-
readable global navigation information, conforming to the constraints expressed in EPUB
Navigation Documents [ContentDocs301] .
Scripted Content Document
4 © ISO/IEC 2020 – All rights reserved

An EPUB Content Document that includes scripting or an XHTML Content Document that
contains HTML5 forms elements.
Refer to Scripted Content Documents [ContentDocs301] for more information.
Top-level Content Document
An EPUB Content Document referenced from the spine, whether directly or via a fallback
chain [Publications301] .
Fixed-Layout Document
An EPUB Content Document directly referenced from the spine that has been designated
pre-paginated in the Package Document, as defined in The rendition:layout Property
[Publications301] .
The dimensions to use for rendering Fixed-Layout Documents are defined in Fixed-Layout
Documents [ContentDocs301] .
Synthetic Spread
The rendering of two adjacent pages simultaneously on a device screen.
Core Media Type
A set of Publication Resource types for which no fallback is required. Refer to Publication
Resources for more information.
Package Document
A Publication Resource carrying bibliographical and structural metadata about a given
Rendition of an EPUB Publication, as defined in Package Documents .
Unique Identifier
The Unique Identifier is the primary identifier for an EPUB Publication, as identified by the
unique-identifier attribute. The Unique Identifier may be shared by one or many
Renditions of the same EPUB Publication that conform to the EPUB standard and embody
the same content.
The Unique Identifier is less granular than the ISBN. However, significant revision,
abridgement, etc. of the content requires a new Unique Identifier.
Release Identifier
The Release Identifier allows any instance of an EPUB Publication to be compared against
another to determine if they are identical, different versions, or unrelated.
Refer to Release Identifier for more information.
Manifest
A list of all Publication Resources that constitute the given Rendition of a EPUB
Publication.
Refer to manifest for more information.
Spine
An ordered list of Publication Resources, typically EPUB Content Documents, representing
the default reading order of the given Rendition of an EPUB Publication.
© ISO/IEC 2020 – All rights reserved 5

ISO/IEC 23736-1:2020(E)
Refer to spine for more information.
Media Overlay Document
An XML document that associates the XHTML Content Document with pre-recorded audio
narration in order to provide a synchronized playback experience, as defined in
[MediaOverlays301].
Text-to-Speech (TTS)
The rendering of the textual content of an EPUB Publication as artificial human speech
using a synthesized voice.
EPUB Style Sheet (or Style Sheet)
A CSS Style Sheet conforming to the CSS profile defined in EPUB Style Sheets
[ContentDocs301] .
Viewport
The region of an EPUB Reading System in which the content of an EPUB Publication is
rendered visually to a User.
CSS Viewport
A Viewport capable of displaying CSS-styled content.
EPUB Container (or Container)
The ZIP-based packaging and distribution format for EPUB Publications defined in
[OCF301].
Author
The person(s) or organization responsible for the creation of an EPUB Publication, which is
not necessarily the creator of the content and resources it contains.
User
An individual that consumes an EPUB Publication using an EPUB Reading System.
EPUB Reading System (or
...