Information technology -- Digital publishing -- EPUB 3.0.1

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) EPUBContainer. 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.

Technologies de l'information -- Publications numériques -- EPUB 3.0.1

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Published
Publication Date
18-Feb-2020
Current Stage
6060 - International Standard published
Start Date
02-Jan-2020
Completion Date
19-Feb-2020
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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 23736-2:2020(E)
ISO/IEC 2020
---------------------- Page: 1 ----------------------
ISO/IEC 23736-2:2020(E)
COPYRIGHT PROTECTED DOCUMENT
© 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
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/IEC 2020 – All rights reserved
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ISO/IEC 23736-2:2020(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 (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
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ISO/IEC 23736-2:2020(E)
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.

Copyright © 2010-2013 International Digital Publishing Forum™

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
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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
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ISO/IEC 23736-2:2020(E)
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
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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
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ISO/IEC 23736-2:2020(E)

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.
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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 Reading System)
A system that processes EPUB Publications for presentation to a User in a manner
conformant with this specification and its sibling specifications .
User Agent

A client or application that consumes generic HTML (e.g., Web browser, screen readers)

› 1.3 Typographic Conventions
The following typographic conventions are used in this specification:
markup

All markup (elements, attributes, properties), code (JavaScript, pseudo-code), machine

processable values (string, characters, media types) and file names are in red-orange

monospace font.
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ISO/IEC 23736-2:2020(E)
markup

Links to markup and code definitions are underlined and in red-orange monospace font. Only

the first instance in each section is linked.
http://www.idpf.org/
URIs are in navy blue monospace font.
hyperlink
Hyperlinks are underlined and in blue.
[reference]
Normative and informative references are enclosed in square brackets.
Term
Terms defined in the Terminology are in capital case.
Term

Links to term definitions have a dotted blue underline. Only the first instance in each section is

linked.
Normative element, attribute and property definitions are in blue boxes.
Informative markup examples are in white boxes.
NOTE
Informative notes are in yellow boxes with a "Note" header.
CAUTION
Informative cautionary note are in red boxes with a "Caution" header.
› 1.4 Conformance Statements

The keywords MUST, MUST NOT, REQUIRED, SHALL, SHALL NOT, SHOULD, SHOULD NOT, RECOMMENDED, MAY,

and OPTIONAL in this document are to be interpreted as described in [RFC2119].

All sections of this specification are normative except where identified by the informative status label

"This section is informative". The application of informative status to sections and appendices applies

to all child content and subsections they may contain.
All examples in this specification are informative.
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ISO/IEC 23736-1:2020(E)
› 2 EPUB Publications

This section defines conformance requirements for EPUB Publications and EPUB Reading Systems

at the Rendition level. Conformance requirements particular to specific Publication Resources and

processing contexts are located in the specifications referenced herein.
› 2.1 Content Conformance
Each Rendition of an EPUB Publication MUST meet all of the following criteria:
All Publication Resources

All Publication Resources MUST be listed in the Package Document (as defined in manifest),

adhere to the constraints for Core Media Types and Fallback and be located as per Publication

Resource Locations.
The Package Document
It MUST contain exactly one Package Document, which MUST conform to the content
requirements defined in Package Document — Content Conformance.
Content Documents

It MUST contain at least one EPUB Content Document conformant to the content requirements

defined in EPUB Content Documents [ContentDocs301] .
The EPUB Navigation Document
It MUST contain exactly one EPUB Navigation Document conformant to the content
requirements defined in EPUB Navigation Documents — Content Conformance
[ContentDocs301] .
EPUB Style Sheets

It MAY contain zero or more EPUB Style Sheets conformant to the content requirements

defined in EPUB Style Sheets — Content Conformance [ContentDocs301] .
EPUB Pronunciation Lexicons

It MAY contain zero or more PLS Documents conformant to the content requirements defined in

PLS Documents — Content Conformance [ContentDocs301] .
Media Overlay Documents

It MAY contain zero or more Media Overlay Documents conformant to the content requirements

defined in [MediaOverlays301].
Additional Publication Resources

It MAY contain zero or more Publication Resources in addition to those listed above, each of

which MUST adhere to the requirements in All Publication Resources.
Container
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ISO/IEC 23736-2:2020(E)
It MUST be packaged in a EPUB Container as defined in [OCF301].
› 2.2 Reading System Conformance
An EPUB Reading System MUST meet all of the following criteria:
EPUB 3 Processing
It MUST process the EPUB Container as defined in [OCF301].

It MUST process the Package Document as defined in Package Document — Reading System

Conformance, and honor all presentation logic expressed through the Package Document (e.g.,

the reading order, fallback chains, bindings, page progression direction and fixed layouts).

It MUST NOT fail catastrophically if it encounters two distinct EPUB Publications with the same

Unique Identifier.

Unless specified as conditional behavior in this section, it MUST support all Core Media Type

Resources.

It MAY support an arbitrary set of Foreign Resource types, and MUST process fallbacks for

unsupported Foreign Resources as defined in Restrictions and Fallbacks if not.
It MUST process XHTML Content Documents as defined in XHTML Content Documents —
Reading System Conformance [ContentDocs301] .

It MUST process SVG Content Documents as defined in SVG Content Documents — Reading

System Conformance [ContentDocs301] .

If it has a CSS Viewport , it MUST support visual rendering of XHTML Content Documents as

defined in EPUB Style Sheets — Reading System Conformance [ContentDocs301] .

If it has the capability to render raster images, it MUST support the raster image Core Media

Types.

If it has the capability to render vector images, it MUST support the vector image Core Media

Types.

If it has the capability to render pre-recorded audio, it MUST support the MP3 audio Core Media

Type, SHOULD support the MP4 audio Core Media Type and SHOULD support Media Overlays

[MediaOverlays301].
If it supports Text-to-Speech (TTS) rendering, it SHOULD support PLS Documents

[ContentDocs301] , the CSS3 Speech features of the EPUB CSS Profile [ContentDocs301] and

SSML attributes [ContentDocs301] in XHTML Content Documents.

It MUST support the EPUB Canonical Fragment Identifiers scheme [EPUBCFI] for linking, and

MAY support additional linking schemes as defined in the EPUB Linking Scheme Registry.

NOTE

It is recommended that Reading Systems support at least one of the [H.264] and [VP8]

video codecs, but this is not a conformance requirement; a Reading System may support

no video codecs at all. Content creators and Reading System developers should take

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ISO/IEC 23736-1:2020(E)

into consideration factors such as breadth of adoption, video playback quality, and

technology usage royalty requirements when making a choice to include or implement

video in either (or potentially, both) formats.
Backward Compatibility

It SHOULD process EPUB version 2 Publications as defined in [OPF2], [OPS2] and [OCF2].

It MUST attempt to process any given Rendition of an EPUB Publication whose Package

Document version attribute designates a version lower than "3.0" or which omits the version

attribute.
Forward Compatibility

It SHOULD attempt to process any given Rendition of an EPUB Publication whose Package

Document version attribute designates a version higher than "3.0".
XML Processing
It MUST be a conformant non-validating processor [XML].
It MUST be a conformant processor as defined in [XMLNS].

It MUST support xml-stylesheet processing instructions [ASSOCSS], and MAY support

additional processing instructions.
It MUST be a conformant application as defined by [XML Base].
NOTE

A conforming Reading System is not necessarily a single dedicated program or device, but

may exist as a distributed system.
› 3 Package Documents
› 3.1 Introduction
This section is informative

The Package Document carries bibliographic and structural metadata about a Rendition of an EPUB

Publication, and is thus the primary source of information about how to process and display that

Rendition.

The Package Document is an XML document consisting of a set of container elements, each

dedicated to housing information about a particular aspect of the Rendition. These containers

effectively centralize metadata, detail the individual resources that compose the Rendition and

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ISO/IEC 23736-2:2020(E)

provide reading order and other information for rendering the EPUB Publication is represents to a

User.
The following list summarizes the information a Package Document contains:

Rendition metadata — mechanisms for including and/or referencing metadata applicable to the

EPUB Publication and/or the specific Rendition of it, including for particular resources within the

Rendition.

A manifest — identifies (via IRI) and describes (via MIME media type) the set of resources that

collectively compose the given Rendition of the EPUB Publication.

A spine — an ordered sequence of ID references to top-level resources in the manifest from

which all other resources in the set can be reached or utilized. The spine defines the default

reading order of the given Rendition.

Fallback chains — an optional means for defining an ordered list of top-level resources that can

be considered content equivalents that a Reading System can choose between for rendering.

Bindings — an optional means of associating script-based implementations with custom media

types.
› 3.2 Content Conformance
A Package Document MUST meet all of the following criteria:
Document Properties

It MUST meet the conformance constraints for XML documents defined in XML Conformance.

It MUST be valid to the Package Document schema, as defined in Appendix A, Package

Document Schema , and conform to all content conformance constraints expressed in Package

Document Definition.
File Properties
The Package Document filename SHOULD use the file extension .opf.

Package Documents have the MIME media type application/oebps-package+xml [RFC4839].

› 3.3 Reading System Conformance
An EPUB Reading System MUST meet all of the following criteria:
Processing

It MUST process the Package Document in conformance with all Reading System conformance

constraints expressed in Package Document Definition.
It SHOULD process presentational metadata, as expressed in General Properties
It MUST process fixed layout metadata, as expressed in Fixed-Layout Properties
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ISO/IEC 23736-1:2020(E)

For fixed layouts expressed using the rendition:layout property, it MUST determine the

rendering dimensions as defined in Fixed-Layout Documents [ContentDocs301] .

It MUST ignore proprietary metadata properties that pertain to layout expressions if they conflict

behaviorally with the property semantics defined in Fixed-Layout Properties.
› 3.4 Package Document Definition

All elements [XML] defined in this section are in the http://www.idpf.org/2007/opf namespace

[XMLNS] unless otherwise specified.
› 3.4.1 The package Element

The package element is the root container of the Package Document and encapsulates metadata and

resource information for a Rendition.
Element Name
package
Usage
The package element is the root element of the Package Document.
Attributes
version [required]
Specifies the EPUB specification version to which the given Rendition conforms.

The attribute MUST have the value 3.0 to indicate compliance with this version of the

specification.
unique-identifier [required]
An IDREF [XML] that identifies the dc:identifier element that provides the
package's preferred, or primary, identifier.
Refer to Publication Identifiers for more information.
prefix [optional]
Declaration mechanism for prefixes not reserved by this specification.
Refer to The prefix Attribute for more information.
xml:lang [optional]
Specifies the language used in the contents and attribute values of the carrying

element and its descendants, as defined in section 2.12 Language Identification of

[XML].
dir [optional]
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ISO/IEC 23736-2:2020(E)

Specifies the base text direction of the content and attribute values of the carrying

element and its descendants.

Inherent directionality specified using [Unicode] takes precedence over this attribute.

Allowed values are ltr (left-to-right) and rtl (right-to-left).
id [optional]
The ID [XML] of this element, which MUST be unique within the document scope.
Content Model
In this order: metadata [required], manifest [required], spine [required], guide
[optional/deprecated], bindings [optional], collection [0 or more]
› 3.4.2 The metadata Element
The metadata element encapsulates meta information for the given Rendition.
Element Name
metadata
Usage
Required first child of package .
Attributes
The metadata element has no attributes defined in this specification.
Content Model
In any order: dc:identifier [1 or more], dc:title [1 or more], dc:language [1 or

more], DCMES Optional Elements [0 or more], meta [1 or more], OPF2 meta [0 or more],

link [0 or more]

The minimal required metadata that each Rendition of an EPUB Publication MUST include consists of

three elements from the Dublin Core Metadata Element Set [DCMES] — title , identifier and

language — together with the modified property from DCMI Metadata Terms [DCTERMS]. Refer to

the example at the end of this section for an instance of a complete minimal metadata set.

Additional optional metadata is expressed using the DCMES optional elements and the meta

element.
› Examples

The following example represents the minimal set of metadata that all Renditions have to contain.




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ISO/IEC 23736-1:2020(E)
urn:uuid:A1B0D67E-2E81-4DF5-9E67-
A64CBE366809
Norwegian Wood
en
2011-01-01T12:00:00Z



› 3.4.3 The DCMES identifier Element

The [DCMES] identifier element contains a single identifier associated with the given Rendition of

the EPUB Publication, such as a UUID, DOI, ISBN or ISSN.
Element Name
dc:identifier
Namespace
http://purl.org/dc/elements/1.1/
Usage
Required child of metadata . Repeatable.
Attributes
id [optional]
The ID [XML] of this element, which MUST be unique within the document scope.
The id attribute is required on the identifier element containing the unique
identifier. See below.
Content Model
Text

Every Rendition's metadata section MUST include at least one identifier element containing an

unambiguous identifier for the EPUB Publication. Multiple identi
...

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