EPUB3 Specification

EPUB Publication

*Rendition(s)

*Package Document (package)

ATTRIBUTES:

*unique-identifier

The primary identifier for an EPUB Publication, as identified by the unique-identifier attribute. The Unique Identifier can be shared by one or more Renditions of the same EPUB Publication. Significant revision, abridgement, etc. of the content requires a new Unique Identifier.

dir

ltr

Left to Right

rtl

Right to Left

href

absolute / relative url

media-type

application/xml

properties

A space-separated list of property values

refines

Identifies the expression or resource augmented by the element.

xml:lang

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].

CONTENT (in this order):
1) metadata
2) manifest
3) spine
4) collection

*metadata

General information about the EPUB Publication allowing titles, authors, identifiers, and other info to be easily accessed.

ATTRIBUTES:

NONE

CONTENT Model (in any order):

*dc:identifier

<dc:identifier id="pub-id">
urn:uuid:A1B0D67E-2E81-4DF5-9E67-A64CBE366809
</dc:identifier>

*dc:title

*dc:language

OPTIONAL ELEMENTS:

contributor

The [DC11] contributor element is used to represent the name of a person, organization, etc. that played a secondary role in the creation of the content of an EPUB Publication.

coverage

creator

The [DC11] creator element represents the name of a person, organization, etc. responsible for the creation of the content of the Rendition. The role property can be attached to the element to indicate the function the creator played in the creation of the content.

description

date

The date element MUST only be used to define the publication date of the EPUB Publication. The publication date is not the same as the last modified date (the last time the Rendition was changed). It is RECOMMENDED that the date string conform to [ISO8601], particularly the subset expressed in W3C Date and Time Formats [DateTime], as such strings are both human and machine readable.

Only one date element is allowed.

format

publisher

relation

rights

source

subject

The [DC11] subject element identifies the subject of the EPUB Publication. The value of the element SHOULD be the human-readable heading or label, but MAY be the code value if the subject taxonomy does not provide a separate descriptive label.

Authors MAY identify the system or scheme the element's value is drawn from using the authority property.

When a scheme is identified, a subject code MUST be attached using the term property.

type

The [DC11] type element is used to indicate that the given EPUB Publication is of a specialized type (e.g., annotations or a dictionary packaged in EPUB format). An informative registry of specialized EPUB Publication types for use with this element is maintained in the [TypesRegistry], but Authors MAY use any text string as a value.

*meta

The meta element provides a generic mechanism for including metadata properties from any vocabulary. It is typically used to include rendering metadata defined in EPUB specifications, but MAY be used for any metadata purposes.

ATTRIBUTES:

dir

*property

Reserved Options

title-type

term

source-of

role

identifier-type

group-position

file-as

display-seq

collection-type

belongs-to-collection

authority

alternate-script

media:active-class

media:duration

media:narrator

media:playback-active-class

Any non-reserved option

refines

scheme

xml:lang

link

Used to attach complete
bibliographic records, etc
as part of the metadata.

Linked resources are not Publication Resources and MUST NOT be listed in the manifest. A linked resource MAY be embedded in a Publication Resource that is listed in the manifest, however, in which case it MUST be a Core Media Type Resource [EPUB32] (e.g., an EPUB Content Document could contain a metadata record serialized as [RDFA-CORE] or [JSON-LD]).

Core Media Type Resource

image/gif

image/jpeg

image/png

image/svg+xml

audio/mpeg

audio/mp4

text/css

Videos

Fonts

Other

ATTRIBUTES:

*href

*media-type

properties

OPTIONS:

onix

The ONIX for Books standard provides a free-to-use format for passing descriptive metadata about books between publishers, data aggregators, book retailers and other interested parties in the publishing industry. Metadata concerning one or more book titles can be stored in a suitably formatted XML file known as an 'ONIX message' ready for dissemination. Whereas other data standards exist for storing the contents of a book - the text, layout and graphics - the ONIX for Books standard holds information about the book, similar to, but more extensive than, the information one would typically find on the cover or title page of a printed book or in a library catalog. The ONIX for Books standard provides a way to communicate information about a book's author, publisher, price, publication date, physical dimensions, synopsis and many other details besides. The standard is quite extensive and most publishers currently provide only a few dozen of the many hundreds of pieces of information that the standard is designed to carry.

xmp

The Extensible Metadata Platform (XMP) is an ISO standard, originally created by Adobe Systems Inc., for the creation, processing and interchange of standardized and custom metadata for digital documents and data sets.

XMP standardizes a data model, a serialization format and core properties for the definition and processing of extensible metadata. It also provides guidelines for embedding XMP information into popular image, video and document file formats, such as JPEG and PDF, without breaking their readability by applications that do not support XMP. Therefore, the non-XMP metadata have to be reconciled with the XMP properties. Although metadata can alternatively be stored in a sidecar file, embedding metadata avoids problems that occur when metadata is stored separately.

refines

*rel

OPTIONS:

acquire

alternate

record

voicing

Namespace:

xmlns:dc="http://purl.org/dc/elements/1.1/";

*manifest

Identifies and describes the set of resources that collectively compose the given Rendition

Manifest Fallback Chains

Are: A mechanism that defines an ordered list of top-level resources as content equivalents. A reading system can then choose between the resources based on which it is capable of rendering.

ATTRIBUTES:

CONTENT:

*item

ATTRIBUTES

*fallback

The fallback attribute takes an IDREF [XML] that identifies a fallback for the Publication Resource referenced from the item element. Fallbacks MAY be provided for Core Media Type Resources (e.g., to provide a static alternative to a Scripted Content Document). Fallback requirements for Foreign Resources are defined in Manifest Fallbacks.

*href

*id

media-overlay

*media-type

properties

OPTIONS:

cover-image

*mathml

*nav

*remote-resources

*scripted

*svg

Represents a Publication Resource

Each item element in the manifest identifies a Publication Resource by the IRI [RFC3987] provided in its href attribute. The IRI MAY be absolute or relative. In the case of relative IRIs, Reading Systems MUST use the IRI of the Package Document as the base when resolving these to absolute IRIs. The resulting absolute IRI MUST be unique within the manifest scope.

*spine

Provides an external declarative means to explicitly specify navigation through a collection of documents

IS: 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.

ATTRIBUTES:

page-progression-direction

The page-progression-direction attribute sets the global direction in which the content flows.

ltr

rtl

default

CONTENT:

*itemref

ATTRIBUTES

*idref

linear

The linear attribute indicates whether the referenced item contains content that contributes to the primary reading order and has to be read sequentially ("yes") or auxiliary content that enhances or augments the primary content and can be accessed out of sequence ("no"). Examples of auxiliary content include: notes, descriptions and answer keys. An itemref that omits the linear attribute is assumed to have the value "yes".

yes

properties

CONTENT:

EMPTY!

Each itemref element MUST reference the ID [XML] of a unique item in the manifest via the IDREF [XML] in its idref attribute (i.e., two or more itemref elements cannot reference the same item). Each referenced manifest item MUST be either a) an EPUB Content Document or b) another type of Publication Resource which, regardless of whether it is a Core Media Type Resource or a Foreign Resource, MUST include an EPUB Content Document in its fallback chain.

collection

Allows grouping of logically-related Publication Resources. Enables the development of specialized content identification, processing and rendering features, such as the ability to define embedded preview content, or assemble an index or dictionary from its constituent XHTML Content Documents.

ATTRIBUTES

*role

dir

xml:lang

CONTENT (In this order):
1) metadata [0 or 1]
2) collection [1...N], or
collection [0+] link [1+]

metadata

*collection

collection link

*Navigation Document (nav)

General Info

Replaces the EPUB2 NCX Document

Natively supports embedded grammars (e.g. MathML, SVG, etc)

MUST Conform to:

An XHTML Document (using the HTML nav element) to define human/machine readable navigation information.

It MUST conform to the content conformance constraints specific to EPUB Navigation Documents defined in EPUB Navigation Document Definition.

CONTENT MODEL:

*ol

CONTENT:

*li

CONTENT:

*span or a

An a element MAY be followed by an ol ordered list representing a subsidiary content level below that heading (e.g., all the subsection headings of a section).

A span element MUST be followed by an ol ordered list; it cannot be used in "leaf" li elements.

*ol

ATTRIBUTES

The ol child of the nav element represents the primary level of content navigation.

HTML Heading Content

e.g. h1, h2, ....

ATTRIBUTES

*epub:type

1 of these REQUIRED

landmarks

Identifies the nav element that contains a list of points of interest.

page-list

Identifies the nav element that contains a list of pages for a print or other statically-paginated source for the EPUB Publication.

toc

Identifies the nav element that contains the table of contents. The toc nav is the only navigation aid that has to be included in the EPUB Navigation Document.

hidden

There are three types of EPUB nav elements. Specify which one is being used through the epub:type attribute

OTHER types are OK also.

*Content Documents (a.k.a Publication Resources)

General

XHTML or SVG documents that describe the readable content and reference associated media resources (e.g. images, audio and video clips)

Also supports embedded fonts

Content presentation should adapt to the user preferences

Designed to maximize accessibility for the visually impaired, and Reading Systems typically perform text line layout and pagination on the fly, adapting to the size of the display area, the user's preferred font size, and other environmental factors

An EPUB Content Document MUST NOT be referenced by more than one Media Overlay Document.

Multimedia

video

audio

Text-To-Speech

Pronunciation Lexicons

The inclusion of generic pronunciation lexicons using the W3C PLS format [PRONUNCIATION-LEXICON] enables Authors to provide pronunciation rules that apply to the entire EPUB Publication.

Inline SSML Phonemes

The incorporation of SSML phonemes functionality [SSML] directly into a EPUB Content Document enables fine-grained pronunciation control, taking precedence over default pronunciation rules and/or referenced pronunciation lexicons (as provided by the PLS format mentioned above). Refer to SSML Attributes [ContentDocs32] for more information.

Media Overlay Documents (smil)

When pre-recorded narration is available for a Rendition of an EPUB Publication, Media Overlays provide the ability to synchronize that audio with the text of a Content Document (see also Aural Renditions and Media Overlays).

Style Information

Visual rendering information for the currently-playing EPUB Content Document element MAY be expressed in the CSS Style Sheet using author-defined classes. These author-defined class names SHOULD be declared in the Package Document metadata using the metadata properties active-class and playback-active-class. The class names are then discoverable by Reading Systems.

The active-class and playback-active-class properties MUST NOT be used in conjunction with a refines attribute [Packages32], as they are always considered to apply to the entire Rendition.

Including in the Manifest

If an EPUB Content Document is wholly or partially referenced by a Media Overlay, then its manifest item element [Packages32] MUST include a media-overlay attribute. The attribute MUST reference the ID [XML] of the manifest item for the corresponding Media Overlay Document.

The media-overlay attribute MUST NOT be attached to manifest item elements that do not reference EPUB Content Documents.

Manifest items for Media Overlay Documents MUST have the media type application/smil+xml.

CONSTRAINTS

It MUST meet the conformance constraints for XML documents defined in XML Conformance [EPUB32].

It MUST be valid to the Media Overlays schema as defined in Appendix A, Media Overlays Schema and conform to all content conformance constraints expressed in Media Overlay Document Definition.

It MUST be authored to reflect the structure of the EPUB Content Document with which it is associated, as stated in Structure.

It MAY refer to more than one EPUB Content Document, but an EPUB Content Document MUST NOT be referenced by more than one Media Overlay Document.

It MUST adhere to the requirements for Embedded Media.

It SHOULD use semantic markup where appropriate, as described in Semantic Inflection.

It MUST be packaged with the EPUB Publication as shown in Packaging.

The Media Overlay Document filename SHOULD use the file extension .smil.

NAMESPACE

smil

https://www.w3.org/ns/SMIL

ATTRIBUTES

*version

This attribute MUST have the value "3.0".

epub:prefix

CONTENT (In this order):
1) head [0 or 1]
2) body [exactly 1]

head

NO ATTRIBUTES

CONTENT

metadata

NO ATTRIBUTES

CONTENT

0 or more elements from any namespace

*body

ATTRIBUTES

epub:type

epub:textref

CONTENT

seq

ATTRIBUTES

epub:type

*epub:textref

CONTENT

seq

par

IMPORTANT: At least one par or seq is required

The seq element contains media objects which are to be rendered sequentially.

par

The par element contains media objects which are to be rendered in parallel.

ATTRIBUTES

epub:type

CONTENT

*text

ATTRIBUTES

*src

NO CONTENT

The text element references an element in the EPUB Content Document. A text element typically refers to a textual element, but can also refer to other EPUB Content Document media elements (see Embedded Media).

audio

The audio element is OPTIONAL only if its sibling text element refers to audio or video media (see Embedded Media), or to textual content intended for rendering via Text-to-Speech (TTS).

ATTRIBUTES

*src

clipBegin

A clock value that specifies the offset into the physical media corresponding to the start point of an audio clip. MUST be a [SMIL3] clock value.

clipEnd

A clock value that specifies the offset into the physical media corresponding to the end point of an audio clip. MUST be a [SMIL3] clock value.

NO CONTENT

IMPORTANT: At least one par or seq is required

CONFORMANCE

It MUST be an [HTML] document that conforms to the XHTML syntax.

It MUST meet the conformance constraints for XML documents defined in XML Conformance [EPUB32].

For all document constructs used that are defined by [HTML], it MUST conform to the conformance criteria defined for those constructs in that specification, unless explicitly overridden in HTML Deviations and Constraints.

It MAY include extensions to the [HTML] grammar as defined in HTML Extensions, and MUST conform to all content conformance constraints defined therein.

The XHTML Content Document filename SHOULD use the file extension .xhtml

ATTRIBUTES

epub:type

Reserved Options (EPUB-SSV):

backmatter

bodymatter

cover

frontmatter

chapter

division

part

volume

abstract

afterword

conclusion

epigraph

epilogue

foreword

introduction

preamble

preface

prologue

landmarks

loa

loi

lot

lov

toc

toc-brief

appendix

colophon

credits

keywords

biblioentry

bibliography

antonym-group

condensed-entry

def

dictentry

dictionary

etymology

example

gram-info

idiom

part-of-speech

part-of-speech-list

part-of-speech-group

phonetic-transcription

phrase-list

phrase-group

sense-list

sense-group

synonym-group

tran

tran-info

glossary

glossdef

glossterm

index

index-editor-note

index-entry

index-entry-list

index-group

index-headnotes

index-legend

index-locator

index-locator-list

index-locator-range

index-term

index-term-categories

index-term-category

index-xref-preferred

index-xref-related

acknowledgments

contributors

dedication

errata

halftitlepage

imprimatur

imprint

other-credits

revision-history

seriespage

titlepage

case-study

notice

pullquote

tip

covertitle

fulltitle

ordinal

subtitle

title

learning-objective

learning-objectives

learning-outcome

learning-outcomes

learning-resource

learning-resources

learning-standard

learning-standards

answer

answers

assessments

feedback

fill-in-the-blank-problem

general-problem

match-problem

multiple-choice-problem

practice

practices

qna

question

true-false-problem

balloon

panel

panel-group

sound-area

text-area

endnote

endnotes

footnote

footnotes

backlink

biblioref

glossref

noteref

concluding-sentence

credit

keyword

topic-sentence

page-list

pagebreak

table

table-row

table-cell

list

list-item

figure

aside

prefix

prism

msv

ssml

alphabet

HTML Deviations & Constraints

Embedded MathML

Embedded SVG

Form Submission

Reading System support for the submission of [HTML] forms is OPTIONAL. A Reading System might, for example, prevent form submissions by limiting access to networking.

SVG Content Documents

CONFORMANCE

It MUST meet the conformance constraints for XML documents defined in XML Conformance [EPUB32].

It MUST be an SVG document fragment [SVG], and conform to all content conformance constraints expressed in Restrictions on SVG.

Restrictions

foreignObject

title

The SVG Content Document filename SHOULD use the file extension .svg

It MAY include references to Foreign Resources provided a fallback to a Core Media Type Resource is included.

CSS Documents

CONFORMANCE

direction

unicode-bidi

It MAY include the prefixed properties defined in CSS Style Sheets — Prefixed Properties.

It MUST be encoded in UTF-8 or UTF-16 [Unicode].

Writing Modes

-epub-text-orientation:

upright

mixed

sideways-right

sideways

mixed

-epub-writing-mode

horizontal-tb

vertical-rl

vertical-lr

-epub-text-combine

-epub-text-combine-horizontal

none

all

Text Level 3

-epub-hyphens

none

manual

auto

all

-epub-line-break

auto

loose

normal

strict

-epub-text-align-last

auto

start

end

left

right

center

justify

-epub-word-break

normal

keep-all

break-all

text-transforms

-epub-fullwidth

Text Decoration Level 3

-epub-text-emphasis-color

<color>

-epub-text-emphasis-position

over | under

right | left

-epub-text-emphasis-style

none

dot | circle | double-circle | triangle | sesame

filled | open

-epub-text-underline-position

auto

under

left | right

-epub-text-underline-position

alphabetic

Fixed Layout Documents

CONFORMANCE

It MUST specify its initial containing block [CSS2] as defined in Initial Containing Block Dimensions.

When rendering Fixed-Layout Documents, the default intent is that the Content Display Area SHOULD occupy as much of the available Viewport area as possible.

Reading Systems SHOULD NOT inject additional content such as border, margins, headers or footers into the Viewport.

For XHTML Fixed-Layout Documents, the initial containing block [CSS2] dimensions MUST be expressed in a viewport meta tag using the syntax defined in [CSS-Device-Adapt-1]. In this version of this specification, only the width and height expressions MUST be recognized by Reading Systems.

For SVG Fixed-Layout Documents, the ICB dimensions MUST be expressed using the viewBox attribute [SVG].

Pronunciation Lexicon (PLS) Documents

CONFORMANCE

PLS Documents MAY be associated with XHTML Content Documents. Each XHTML Content Document MAY contain zero or more PLS document associations.

PLS documents MUST be associated with the XHTML Content Document to which they apply using the [HTML] link element with its rel attribute set to "pronunciation" and its type attribute set to the media type "application/pls+xml".

The link element hreflang attribute SHOULD be specified on each link, and its value MUST match the language for which the pronunciation lexicon is relevant [PRONUNCIATION-LEXICON] when specified.

PLS documents MUST meet the content conformance criteria defined in PLS Documents — Content Conformance.

PLS documents MUST be represented and located as defined in EPUB Package — Conformance [Packages32].

Document Properties

It MUST meet the conformance constraints for XML documents defined in XML Conformance [EPUB32].

It MUST be valid to the RELAX NG schema for PLS documents available at the URI https://www.w3.org/TR/2008/REC-pronunciation-lexicon-20081014/ [PRONUNCIATION-LEXICON].

The PLS document filename SHOULD use the file extension .pls.

epubReadingSystem (Javascript Object)

CONFORMANCE

Reading Systems MUST expose the epubReadingSystem object on the navigator object of all loaded Scripted Content Documents, including any nested container-constrained scripting contexts.

Reading Systems MUST ensure that the epubReadingSystem object is available no later than when the DOMContentLoaded event is triggered [HTML].

The following properties MUST be made available for retrieving information about the Reading System.

name

version

LayoutStyle

PROPERTIES

name

Returns a String value representing the name of the Reading System (e.g., "iBooks", "Kindle").

version

Returns a String value representing the version of the Reading System (e.g., "1.0", "2.1.1").

LayoutStyle

Use of the layoutStyle property is deprecated. Refer to its definition in [ContentDocs301] for usage information.

METHODS

hasFeature

PARAMS

version

RECOGNIZED FEAUTRES

dom-manipulation

layout-changes

touch-events

mouse-events

keyboard-events

spine-scripting

Additional features MAY be added by Reading System developers, but future versions of this specification might append to this list in ways that could conflict or be incompatible with any such custom additions.

CSS

PLS (Pronunciation Lexicons)

Media Overlay Documents

Other CONFORMANCE

Use the file extension .opf

Is an XML Document & MUST conform to the XML Conformance definition.

Generic Info

Defines a standard way to represent metadata globally applicable to a collection of pages

Fixed Layouts

EPUB3 metadata allows for fixed-layout XHTML Content Documents as well as the inherent capabilities for fixed-layouts in SVG.

Allows authors to specify desired orientation, when to create synthetic spreads, and how to position pages within those spreads.

last-modified

Together with the package identifier provides a means of distinguishing different versions of an EPUB Publication.

Each rendition of an EPUB Publication defines at least one logical ordering of all its top-level content (the spine), as well as a declarative table of contents (the EPUB Navigation Document).

Consists of multiple resources that can be completely navigated and consumed by a person or program in some specific order.

Single container (file) format based on zip with an XML document that identifies the location of the Package Document for each Rendition in the ZIP archive... The XML is located at a pre-defined location in the archive.

EPUB Reading System

Process the Package Document as defined in the conformance section and honor all presentation logic expressed through the Package Documentation

Process the EPUB Navigation Document as described in the conformance section.

Process fixed layout metadata, as expressed in Fixed-Layout Properties.

Process rendering metadata

Ignore proprietary metadata properties that pertain to layout expressions if they conflict behaviorally with the property semantics defined in Fixed-Layout Properties

Use any resources not listed in the Package Document in the processing of the Package.

EPUB Open Container Format (OCF)

CONFORMANCE

An OCF Abstract Container MUST meet the conformance constraints defined in OCF Abstract Container.

ZIP File Requirements

All OCF Abstract Containers MUST include a directory called META-INF in their Root Directory.

This directory contains the files specified in META-INF Reserved Files. Files other than the ones listed in that section MAY be included in the META-INF directory; OCF Processors MUST NOT fail when encountering such files.

An OCF ZIP Container MUST meet the conformance constraints defined in OCF ZIP Container.

File Name Restrictions Apply

Abstract Container File System

META-INF (Folder)

container.xml

signatures.xml

encryption.xml

metadata.xml

rights.xml

manifest.xml

mimetype

ZIP Container

mimetype

Resource Obfuscation

application/epub+zip