Information technology -- Digital publishing -- EPUB 3.0.1
This specification, EPUB Content Documents 3.0.1, defines profiles of HTML5, SVG, and CSS for use in the context of EPUB® Publications. 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 Publications 3.0.1 [Publications301], which defines the semantics and overarching conformance requirements for each Rendition of an EPUB Publication. 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 Content Documents 3.0 [ContentDocs30]. Refer to [EPUB3Changes] for information on differences between this specification and its predecessor.
Technologies de l'information -- Publications numériques -- EPUB 3.0.1
Standards Content (sample)
Information technology — Digital
publishing — EPUB 3.0.1 —
Technologies de l'information — Publications numériques — EPUB
Partie 3: Documents de contenu
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© ISO/IEC 2020
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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
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This document was prepared by the World Wide Web Consortium (W3C) (as EPUB Content Documents
3.0.1) and drafted in accordance with its editorial rules. It was adopted, under the JTC 1 PASprocedure, 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 website.
Any feedback or questions on this document should be directed to the user’s national standards body. Acomplete listing of these bodies can be found at www.iso.org/members.html.
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EPUB Content Documents 3.0.1
Recommended Specification 26 June 2014
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 InternationalDigital Publishing Forum (IDPF).
EPUB is a registered trademark of the International Digital Publishing Forum.
Markus Gylling, International Digital Publishing Forum (IDPF)
William McCoy, International Digital Publishing Forum (IDPF)
Elika J. Etemad, Invited Expert
Matt Garrish, Invited Expert
TABLE OF CONTENTS
1.1. Purpose and Scope
1.2. Relationship to Other Specifications
1.2.1. Relationship to HTML5
1.2.2. Relationship to SVG
1.2.3. Relationship to CSS
1.2.4. Future Maintenance
1.4. Typographic Conventions
1.5. Conformance Statements
1.6. Namespace prefix mappings
2. EPUB Content Documents
2.1. XHTML Content Documents
2.1.1. Content Conformance
2.1.2. Reading System Conformance
2.1.3. HTML5 Extensions
18.104.22.168. Semantic Markup
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22.214.171.124.1. Semantic Inflection
126.96.36.199.1.2. The epub:type Attribute
188.8.131.52.1.3. Vocabulary Association
184.108.40.206.1.4. Processing Requirements
220.127.116.11.2. Semantic Enrichment
18.104.22.168.2.2. Content Conformance
22.214.171.124.2.3. Processing Requirements
126.96.36.199. SSML Attributes
188.8.131.52.2. The ssml:ph attribute
184.108.40.206.3. The ssml:alphabet attribute
220.127.116.11. Content Switching
18.104.22.168.2.1. The epub:switch Element
22.214.171.124.2.2. The epub:case Element
126.96.36.199.2.3. The epub:default Element
188.8.131.52. The epub:trigger Element
184.108.40.206. Alternate Style Tags
220.127.116.11. Custom Attributes
18.104.22.168. The aria-describedat Attribute
2.1.4. HTML5 Deviations and Constraints
22.214.171.124. Embedded MathML
126.96.36.199.2. Content Conformance
188.8.131.52.3. Reading System Conformance
184.108.40.206.4. Alternative Content
220.127.116.11. Embedded SVG
18.104.22.168.1. Embedded SVG and CSS
22.214.171.124. Unicode Restrictions
126.96.36.199. Discouraged Constructs
188.8.131.52. Special Considerations
184.108.40.206.1. The body element
2.2. EPUB Navigation Documents
2.2.2. Content Conformance
2.2.3. Reading System Conformance
2.2.4. EPUB Navigation Document Definition
220.127.116.11. The nav Element: Restrictions
18.104.22.168. The nav Element: Types
22.214.171.124.1. The toc nav Element
126.96.36.199.2. The page-list nav Element
188.8.131.52.3. The landmarks nav Element
184.108.40.206.4. Other nav Elements
220.127.116.11. The hidden attribute
2.3. SVG Content Documents
2.3.2. Content Conformance
2.3.3. Restrictions on SVG 1.1
2.3.4. Reading System Conformance
2.3.5. Semantic Inflection
2.4. Scripted Content Documents
2.4.1. Scripting Contexts
2.4.2. Content Conformance
2.4.3. Reading System Conformance
2.4.4. Security Considerations
2.4.5. Event Model Considerations
2.5. Fixed-Layout Documents
2.5.2. Reading System Conformance
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2.5.3. Viewport Rendering
2.5.4. Content Dimensions for XHTML and SVG
18.104.22.168. Expressing ICB Dimensions in XHTML
22.214.171.124. Expressing ICB Dimensions in SVG
3. EPUB Style Sheets
3.1. Content Conformance
3.2. Reading System Conformance
3.3. EPUB 3 CSS Profile
3.3.1. CSS 2.1
3.3.2. CSS 2.0
3.3.3. CSS 3.0 Speech
3.3.4. CSS Fonts Level 3
3.3.5. CSS Text Level 3
3.3.6. CSS Text Decoration Level 3
3.3.7. CSS Writing Modes
3.3.9. Media Queries
3.3.10. CSS Namespaces
3.3.11. CSS Multi-Column Layout
3.3.12. Ruby Positioning
3.3.13. Display Property Values oeb-page-head and oeb-page-foot [DEPRECATED]
4. PLS Documents
4.2. EPUB Publication Conformance
4.3. Content Conformance
4.4. Reading System Conformance
B. -epub-fullsize-kana Character Mapping Reference
C. Acknowledgements and Contributors
› 1 Overview
› 1.1 Purpose and Scope
This section is informative
This specification, EPUB Content Documents 3.0.1, defines profiles of HTML5, SVG, and CSS foruse in the context of EPUB® Publications.
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 upEPUB 3:
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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 Publications 3.0.1 [Publications301], which defines the semantics and overarchingconformance requirements for each Rendition of an EPUB Publication.
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 processingmodel for synchronization of text and audio.
This specification supersedes EPUB Content Documents 3.0 [ContentDocs30]. Refer to
[EPUB3Changes] for information on differences between this specification and its predecessor.› 1.2 Relationship to Other Specifications
This section is informative
› 1.2.1 Relationship to HTML5
The XHTML document type defined by this specification is based on W3C [HTML5], and inherits all
definitions of semantics, structure and processing behaviors from the HTML5 specification unlessotherwise specified.
In addition, this specification defines a set of extensions to the W3C HTML5 document model thatAuthors may include in XHTML Content Documents.
This specification defines a simplified processing model that does not require Reading Systems to
support scripting, HTML5 forms or the HTML5 DOM. EPUB Reading Systems conformant with this
specification are only required to be able to process a conforming EPUB Content Document. As
support for scripting and HTML5 forms are optional Reading System features, a conformant Reading
System might not be a fully-conformant HTML5 User Agent (i.e., it might not implement the completeHTML5 processing model).
› 1.2.2 Relationship to SVG
This specification defines a restricted subset of SVG 1.1 to represent vector graphics inline in XHTMLContent Documents and as standalone SVG Content Documents.
› 1.2.3 Relationship to CSS
The CSS profile defined in this specification has CSS 2.1 [CSS2.1] as its baseline. Any CSS Style
Sheet that conforms to CSS 2.1 may be used in the context of an EPUB Publication, except as notedin CSS 2.1.
This specification also incorporates features defined by CSS3 Modules and introduces EPUB-specificCSS constructs.
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› 1.2.4 Future Maintenance
This specification references W3C specifications that are not yet final, and incompatible changes to
them may occur in the future that would cause EPUB 3 Content Documents that were previously
conformant to no longer be conformant to the latest versions of the referenced specifications.
The IDPF anticipates revising this specification if and when such incompatible changes occur,updating the normative constraints defined herein as necessary.
› 1.3 Terminology
A collection of one or more Renditions conforming to this specification and its siblingspecifications , 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
A logical document entity consisting of a set of interrelated resources representing onerendering of an EPUB Publication.
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 [Publications301] and bundled in
the EPUB Container file (unless specified otherwise in Publication Resource Locations[Publications301] ).
Examples of resources that are not Publication Resources include those identified by thePackage Document link [Publications301] element and those identified in outbound
hyperlinks that resolve outside the EPUB Container (e.g., referenced from an [HTML5] aelement href attribute).
Core Media Type Resource
A Publication Resource that is a Core Media Type and may therefore be included in theEPUB Publication without the provision of fallbacks [Publications301] .
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 theEPUB Publication without the provision of fallbacks [Publications301] .
XHTML Content Document
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An EPUB Content Document conforming to the profile of [HTML5] defined in XHTML
XHTML Content Documents use the XHTML syntax of [HTML5].
SVG Content Document
An EPUB Content Document conforming to the constraints expressed in SVG Content
EPUB Navigation Document
A specialization of the XHTML Content Document, containing human- and machine-
readable global navigation information, conforming to the constraints expressed in EPUBNavigation Documents.
Scripted Content Document
An EPUB Content Document that includes scripting or an XHTML Content Document thatcontains HTML5 forms elements.
Refer to Scripted Content Documents for more information.
Top-level Content Document
An EPUB Content Document referenced from the spine, whether directly or via a fallbackchain [Publications301] .
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-LayoutDocuments [ContentDocs301] .
Core Media Type
A set of Publication Resource types for which no fallback is required. Refer to PublicationResources [Publications301] for more information.
A Publication Resource carrying bibliographical and structural metadata about a given
Rendition of an EPUB Publication, as defined in Package Documents [Publications301] .Manifest
A list of all Publication Resources that constitute the given Rendition of a EPUBPublication.
Refer to manifest [Publications301] for more information.
An ordered list of Publication Resources, typically EPUB Content Documents, representingthe default reading order of the given Rendition of an EPUB Publication.
Refer to spine [Publications301] for more information.
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The rendering of the textual content of an EPUB Publication as artificial human speechusing a synthesized voice.
EPUB Style Sheet (or Style Sheet)
A CSS Style Sheet conforming to the CSS profile defined in EPUB Style Sheets .
The region of an EPUB Reading System in which the content of an EPUB Publication isrendered visually to a User.
A Viewport capable of displaying CSS-styled content.
A Viewport capable of displaying SVG images.
EPUB Container (or Container)
The ZIP-based packaging and distribution format for EPUB Publications defined in
The person(s) or organization responsible for the creation of an EPUB Publication, which isnot necessarily the creator of the content and resources it contains.
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 .
› 1.4 Typographic Conventions
The following typographic conventions are used in this specification:
processable values (string, characters, media types) and file names are in red-orangemonospace font.
Links to markup and code definitions are underlined and in red-orange monospace font. Onlythe first instance in each section is linked.
URIs are in navy blue monospace font.
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Hyperlinks are underlined and in blue.
Normative and informative references are enclosed in square brackets.
Terms defined in the Terminology are in capital case.
Links to term definitions have a dotted blue underline. Only the first instance in each section islinked.
Normative element, attribute and property definitions are in blue boxes.
Informative markup examples are in white boxes.
Informative notes are in yellow boxes with a "Note" header.
Informative cautionary note are in red boxes with a "Caution" header.
› 1.5 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 appliesto all child content and subsections they may contain.
All examples in this specification are informative.
› 1.6 Namespace prefix mappings
For convenience, the following namespace prefix mappings [XMLNS] are used throughout thisspecification:
prefix namespace URI
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› 2 EPUB Content Documents
› 2.1 XHTML Content Documents
This section defines a profile of [HTML5] for creating XHTML Content Documents. An instance of an
XML document that conforms to this profile is a Core Media Type and is referred to in thisspecification and its sibling specifications as an XHTML Content Document.
Unless otherwise specified, this specification inherits all definitions of semantics, structure andprocessing behaviors from the [HTML5] specification.
The EPUB 3 XHTML Content Document definition references features in the W3C [HTML5]
specification that are still works in progress and may change in incompatible ways. When
utilizing such features, authors should consider the inherent risks in terms of the potentialimpact on interoperability and document longevity.
› 2.1.1 Content Conformance
An XHTML Content Document MUST meet all of the following criteria:
It MUST meet the conformance constraints for XML documents defined in XML Conformance[Publications301] .
It MUST be an [HTML5] document that conforms to the XHTML syntax.
For all document constructs used that are defined by [HTML5], it MUST conform to the
conformance criteria defined for those constructs in that specification, unless explicitlyoverridden in HTML5 Deviations and Constraints.
It MAY include extensions to the [HTML5] grammar as defined in HTML5 Extensions, and MUSTconform to all content conformance constraints defined therein.
The XHTML Content Document filename SHOULD use the file extension .xhtml.
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All Publication Resources referenced from an XHTML Content Document must conform to the
constraints for Publication Resources defined in EPUB Publication — Content Conformance[Publications301]
› 2.1.2 Reading System Conformance
A conformant EPUB Reading System MUST meet all of the following criteria for processing XHTMLContent Documents:
Unless explicitly defined by this specification or its sibling specifications as overridden, it MUST
process XHTML Content Documents using semantics defined by the [HTML5] specification andhonor any applicable User Agent conformance constraints expressed therein.
It MUST meet all Reading System conformance criteria defined in HTML5 Extensions.
It MUST recognize and adapt behaviorally to the constraints defined in HTML5 Deviations andConstraints.
It MUST meet the Reading System conformance criteria defined in Scripted Content Documents— Reading System Conformance.
It MUST support visual rendering of XHTML Content Documents as defined in EPUB StyleSheets — Reading System Conformance.
It SHOULD recognize embedded ARIA markup and support exposure of any given ARIA roles,states and properties to platform accessibility APIs [WAI-ARIA].
› 2.1.3 HTML5 Extensions
This section defines EPUB 3 XHTML Content Document extensions to the underlying [HTML5]document model.
› 126.96.36.199 Semantic Markup
› 188.8.131.52.1 Semantic Inflection
› 184.108.40.206.1.1 Introduction
This section is informative
Semantic inflection is the process of attaching additional meaning about the specific purpose and/or
nature an element plays in an XHTML Content Document. In the context of EPUB Publications, the
epub:type attribute is typically used to express domain-specific semantics, with the inflection(s) it
carries complementing the underlying [HTML5] host vocabulary. The applied semantics always refine
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to indicate a section is a chapter in a work, but cannot be used to turn p elements into list items toavoid proper list structures).
Semantic metadata is not intended for human consumption; it instead provides a controlled way for
Reading Systems and other User Agents to learn more about the structure and content of a
document, providing them the opportunity to enhance the reading experience for Users.
This specification defines a method for semantic inflection using the attribute axis: instead of adding
new XML elements to the XHTML Content Document vocabulary, the epub:type attribute can be
appended to existing elements to inflect the desired semantics. A mechanism to identify externalvocabularies that provide controlled values for the attributes is also defined.
› 220.127.116.11.1.2 The epub:type Attribute
The epub:type attribute inflects semantics on the element on which it appears. Its value is one or
more space-separated terms stemming from external vocabularies associated with the documentinstance, as defined in Vocabulary Association.
The inflected semantic MUST express a subclass of the semantic of the carrying element. In the case
of semantically neutral elements (such as [HTML5] div and span ), the inflected semantic MUST NOT
attach a meaning that is already conveyed by an existing element (e.g., that a div represents a
paragraph or section). Reading Systems MUST ignore inflected semantics that conflict with thecarrying element.
As the [HTML5] head element is a metadata container for a document, structural semantics
expressed on this element or any descendant of it have no meaning. Reading Systems MUST ignoresuch semantics.
The epub:type attribute is intended to be functionally equivalent to the W3C Role Attribute
[Role], but with restrictions as specified in Vocabulary Association. The IDPF's intent is to
harmonize this attribute with W3C mechanisms for semantic inflection in a future majorrevision of the specification.
Global attribute. MAY be specified on all elements.
A space-separated list of property [Publications301] values, with restrictions as defined inVocabulary Association.
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› 18.104.22.168.1.3 Vocabulary Association
This specification adopts the vocabulary association mechanisms defined in Vocabulary AssociationMechanisms [Publications301] , with the following modifications:
› Default Vocabulary
The default vocabulary for Content Documents is defined to be the EPUB 3 Structural SemanticsVocabulary.
› Reserved Prefixes
This specification reserves prefixes that Authors MAY use in the epub:type attribute in the normativedocument EPUB Content Documents Reserved Prefixes.
› The prefix Attribute
The prefix attribute definition is unchanged, but the attribute is defined to be in the namespacehttp://www.idpf.org/2007/ops when used in EPUB Content Documents.
The prefix attribute is only valid on the [HTML5] root html element.
The following example shows the epub:type attribute used to inflect footnote and note referencesemantics. The properties used are defined in the default vocabulary.
… 1 …
The following example shows the epub:type attribute used to inflect glossary semantics on an HTML5definition list. The property used is defined in the default vocabulary.
The following example shows the epub:type attribute used to inflect source publication pagebreak
semantics. The property used is defined in the default vocabulary. (Note that the dc:source
[Publications301] element provides a means of identifying the source publication to which the givenpagination information applies.)
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› 22.214.171.124.1.4 Processing Requirements
A Reading System MUST process the epub:type attribute as follows:
It MAY associate specialized behaviors with none, some or all of the terms defined in the defaultvocabulary.
It MAY associate specialized behaviors with terms given in vocabularies other than the default.It MUST ignore terms that it does not recognize.
When Reading System behavior associated with a given epub:type value conflicts with behavior
associated with the carrying element, the behavior associated with the element MUST be givenprecedence.
› 126.96.36.199.2 Semantic Enrichment
› 188.8.131.52.2.1 Introduction
This section is informative
Unlike semantic inflection, which is about refining the structures within your markup, semantic
enrichment enables the layering of meaning into the content in order to facilitate machine processing.
The [Microdata] and [RDFa11] specifications both define sets of attributes that can be used in XHTMLContent Documents to semantically enrich the content.
› 184.108.40.206.2.2 Content Conformance
A conformant XHTML Content Document MUST meet all of the following criteria:
It MUST allow the use of [Microdata] attributes as defined in that specification.It MUST allow the use of [RDFa11] attributes as defined in [HTML+RDFa11].
› 220.127.116.11.2.3 Processing Requirements
Reading Systems MAY process [Microdata] and [RDFa11] attributes as defined in their respectivespecifications, but such support is OPTIONAL.
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› 18.104.22.168 SSML Attributes
› 22.214.171.124.1 Overview
The W3C Speech Synthesis Markup Language [SSML] is a language used for assisting Text-to-
Speech (TTS) engines in generating synthetic speech. Although SSML is designed as a standalone
document type, it also defines semantics suitable for use within other host languages.
This specification recasts the SSML 1.1 phoneme element as two attributes — ssml:ph andssml:alphabet — and makes them available within EPUB XHTML Content Documents.
Reading Systems with Text-to-Speech (TTS) capabilities SHOULD support the SSML Attributes asdefined below.
For more information on EPUB 3 features related to synthetic speech, refer to Text-to-speech[EPUB3Overview] .
› 126.96.36.199.2 The ssml:ph attribute
The ssml:ph attribute specifies a phonemic/phonetic pronunciation of the text represented by theelement to which the attribute is attached.
Global attribute. May be specified on all elements with which a