ISO/IEC TS 30135-2:2014

Information technology — Digital publishing — EPUB3 — Part 2: Publications

This specification, EPUB Publications 3.0, defines publication-level semantics and conformance requirements for EPUB® 3, including the format of the Package Document 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, 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, which defines profiles of XHTML, SVG and CSS for use in the context of EPUB Publications. - EPUB Open Container Format (OCF) 3.0, 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, which defines a format and a processing model for synchronization of text and audio. This specification supersedes Open Package Format 2.0.1. Refer to EPUB3 changes for information on differences between this specification and its predecessor.

Technologies de l'information — Publications numériques — EPUB3 — Partie 2: Publications

General Information

• Status: Published
• Publication Date: 04-Nov-2014
• ICS: 35.240.30 - IT applications in information, documentation and publishing
• Technical Committee: ISO/IEC JTC 1/SC 34 - Document description and processing languages
• Drafting Committee: ISO/IEC JTC 1/SC 34 - Document description and processing languages
• Current Stage: 9093 - International Standard confirmed
• Completion Date: 01-Apr-2022

Relations

• Consolidated By: ISO 10873:2021 - Dentistry — Denture adhesives
• Effective Date: 06-Jun-2022

Standards Content (Sample)

TECHNICAL ISO/IEC
SPECIFICATION TS
30135-2
First edition
2014-11-15


Information technology — Digital
publishing — EPUB3 —
Part 2:
Publications
Technologies de l'information — Publications numériques — EPUB3 —
Partie 2: Publications




Reference number
ISO/IEC TS 30135-2:2014(E)
©
ISO/IEC 2014

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ISO/IEC TS 30135-2:2014(E)

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©  ISO/IEC 2014
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ii © ISO/IEC 2014 – All rights reserved

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ISO/IEC TS 30135-2:2014(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. In the field of information
technology, ISO and IEC have established a joint technical committee, ISO/IEC JTC 1.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of the joint technical committee is to prepare International Standards. Draft International
Standards adopted by the joint technical committee are circulated to national bodies for voting. Publication as
an International Standard requires approval by at least 75 % of the national bodies casting a vote.
In other circumstances, particularly when there is an urgent market requirement for such documents, the joint
technical committee may decide to publish an ISO/IEC Technical Specification (ISO/IEC TS), which
represents an agreement between the members of the joint technical committee and is accepted for
publication if it is approved by 2/3 of the members of the committee casting a vote.
An ISO/IEC TS is reviewed after three years in order to decide whether it will be confirmed for a further three
years, revised to become an International Standard, or withdrawn. If the ISO/IEC TS is confirmed, it is
reviewed again after a further three years, at which time it must either be transformed into an International
Standard or be withdrawn.
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.
ISO/IEC TS 30135 series were prepared by Korean Agency for Technology and Standards (as KS X 6070
series) with International Digital Publishing Forum and were adopted, under a special “fast-track procedure”,
by Joint Technical Committee ISO/IEC JTC 1, Information technology, in parallel with its approval by the
national bodies of ISO and IEC.
ISO/IEC TS 30135 consists of the following parts, under the general title Information technology — Document
description and processing languages — EPUB 3:
—  Part 1: Overview
—  Part 2: Publications
—  Part 3: Content Documents
—  Part 4: Open Container Format
—  Part 5: Media Overlay
—  Part 6: Canonical Fragment Identifier
—  Part 7: Fixed-Layout Documents

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EPUB Publications 3.0
Recommended Specification 11 October 2011
THIS VERSION
http://www.idpf.org/epub/30/spec/epub30-publications-20111011.html
LATEST VERSION
http://www.idpf.org/epub/30/spec/epub30-publications.html
PREVIOUS VERSION
http://www.idpf.org/epub/30/spec/epub30-publications-20110908.html
A diff of changes from the previous draft is available at this link.
Please refer to the errata for this document, which may include some normative corrections.
Copyright © 2010, 2011 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, DAISY Consortium
William McCoy, International Digital Publishing Forum (IDPF)
Matt Garrish, Invited Expert
TAB LE O F CO NTENTS
1. Overview
1.1. Purpose and Scope
1.2. Terminology
1.3. 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
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

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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
4. Package Metadata
4.1. Publication Identifiers
4.1.1. Unique Identifier
4.1.2. Package Identifier
4.2. Vocabulary Association Mechanisms
4.2.1. Overview
4.2.2. Default Vocabulary
4.2.3. Reserved Vocabularies
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
4.3.3. Metadata link Properties
4.3.4. Manifest item Properties
4.3.5. Spine itemref Properties
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
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, defines publication-level semantics and conformance
requirements for EPUB® 3, including the format of the Package Document 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 [ContentDocs30], which defines profiles of XHTML, SVG and CSS
for use in the context of EPUB Publications.

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EPUB Open Container Format (OCF) 3.0 [OCF3], 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 [MediaOverlays30], which defines a format and a processing model for
synchronization of text and audio.
This specification supersedes Open Package Format 2.0.1 [OPF2]. Refer to [EPUB3Changes] for
information on differences between this specification and its predecessor.
› 1.2 Terminology
EPUB Publication (or Publication)
A logical document entity consisting of a set of interrelated resources and packaged in an
EPUB Container, as defined by this specification and its sibling specifications.
Publication Resource
A resource that contains content or instructions that contribute to the logic and rendering of
the EPUB Publication. In the absence of this resource, the Publication might not render as
intended by the Author. Examples of Publication Resources include the Package Document,
EPUB Content Documents, EPUB Style Sheets, audio, video, images, embedded fonts and
scripts.
With the exception of the Package Document itself, Publication Resources must be listed in
the manifest and must be 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 [ContentDocs30].
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 [ContentDocs30].
EPUB Navigation Document

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A specialization of the XHTML Content Document, containing human- and machine-readable
global navigation information, conforming to the constraints expressed in EPUB Navigation
Documents [ContentDocs30].
Scripted Content Document
An EPUB Content Document that includes scripting or an XHTML Content Document that
contains HTML5 forms elements.
Refer to Scripted Content Documents [ContentDocs30] for more information.
Top-level Content Document
An EPUB Content Document referenced directly from the spine
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 the EPUB
Publication, as defined in Package Documents.
Manifestation
The digital (or physical) embodiment of a work of intellectual content. Changes to the content
such as significant revision, abridgement, translation, or the realization of the content in a
different digital or physical form result in a new manifestation. There may be many individual
but identical copies of a manifestation, termed 'instances' or 'items'. The ISBN is an example
of a manifestation identifier, and is shared by all instances of that manifestation.
All instances of a manifestation need not be bit-for-bit identical, as minor corrections or
revisions are not judged to create a new manifestation or work.
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
Manifestations of the same work that conform to the EPUB standard and embody the same
content, where the differences between the Manifestations are limited to those changes that
take account of differences between EPUB Reading Systems (and which themselves may
require changes in the ISBN).
The Unique Identifier is less granular than the ISBN. However, significant revision,
abridgement, etc. of the content requires a new Unique Identifier.
Package Identifier
The Package Identifier allows any instance of an EPUB Publication to be compared against
another to determine if they are identical, different versions of the same Manifestation, or
unrelated.
Refer to Package Identifier for more information.
Manifest
A list of all Publication Resources that constitute the EPUB Publication.
Refer to manifest for more information.
Spine
An ordered list of Publication Resources, typically EPUB Content Documents, representing

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the default reading order of the Publication.
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
[MediaOverlays30].
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
[ContentDocs30].
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 [OCF3].
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.
› 1.3 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.
› 2 EPUB Publications

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This section defines conformance requirements for EPUB Publications and EPUB Reading Systems at
the Publication level. Conformance requirements particular to specific Publication Resources and
processing contexts are located in the specifications referenced herein.
› 2.1 Content Conformance
An EPUB Publication must meet all of the following criteria:
All Publication Resources
› All Publication Resources it contains must be represented 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 [ContentDocs30].
The EPUB Navigation Document
› It must contain exactly one EPUB Navigation Document conformant to the content requirements
defined in EPUB Navigation Documents — Content Conformance [ContentDocs30].
EPUB Style Sheets
› It may contain zero or more EPUB Style Sheets conformant to the content requirements defined
in EPUB Style Sheets — Content Conformance [ContentDocs30].
EPUB Pronunciation Lexicons
› It may contain zero or more PLS Documents conformant to the content requirements defined in
PLS Documents — Content Conformance [ContentDocs30].
Media Overlay Documents
› It may contain zero or more Media Overlay Documents conformant to the content requirements
defined in [MediaOverlays30].
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
› It must be packaged in a EPUB Container as defined in [OCF3].
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 [OCF3].

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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 and bindings).
› 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 [ContentDocs30].
› It must process SVG Content Documents as defined in SVG Content Documents — Reading
System Conformance [ContentDocs30].
› If it has a CSS Viewport, it must support visual rendering of XHTML Content Documents as
defined in EPUB Style Sheets — Reading System Conformance [ContentDocs30].
› 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
[MediaOverlays30].
› If it supports Text-to-Speech (TTS) rendering, it should support PLS Documents
[ContentDocs30], the CSS3 Speech features of the EPUB CSS Profile [ContentDocs30] and
SSML attributes [ContentDocs30] 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 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 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 Publication whose Package Document version attribute
designates a version higher than 3.0 or which omits the version attribute.
XML Processing

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› 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 an EPUB Publication, and is
thus the primary source of information about how to process and display it.
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 Publication. These containers effectively centralize
metadata for the Publication, detail the individual resources that compose it and provide reading order and
other information for rendering the Publication to a User.
The following list summarizes the information a Package Document contains:
Publication metadata — mechanisms for including and/or referencing metadata applicable to the
entire Publication and particular resources within it.
A Publication manifest — identifies (via IRI) and describes (via MIME media type) the set of
resources that collectively compose the 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 Publication.
Fallback chains — an optional means for Publications to define 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.

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› 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.
› 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 Publication
metadata and resource information.
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 Publication 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.

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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]
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) or 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]
› 3.4.2 The metadata Element
The metadata element encapsulates Publication meta information.
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 Publications 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 Publications must contain.

  …

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    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 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 metadata section must include at least one identifier element containing an unambiguous
identifier for the Publication. Multiple identifier elements are permitted, but only one can be marked as
the Unique Identifier via the package element unique-identifier attribute.
The following example shows the unique identifier element for a Publication.
​
  ​
    urn:uuid:A1B0D67E-2E81-4DF5-9E67-
A64CBE366809​
    …​
  ​

This specification makes a distinction between the Unique Identifier for an EPUB Publication and the
identifier that uniquely identifies a specific version of it (i.e., to be able to differentiate EPUB Publications
containing different versions of the same Manifestation). Two copies of an EPUB that are bit-for-bit

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identical are the same version and must retain the same last modified date. If they are not bit-for-bit
identical, they represent different versions, and must have different last modified dates.
To identify a specific version of a packaged Publication, a Package Identifier can be constructed by
combining the Unique Identifier with the last modified date of the Publication. Changes between versions
may include minor typographic or markup corrections, without affecting the Unique Identifier. Significant
revisions to the content that result in a new edition require a change of the Unique Identifier. For more
information on the semantics and requirements of the Package Identifier, refer to Package Identifier.
This specification imposes no additional restrictions or requirements on identifiers except that they must
be at least one character in length. It is strongly recommended that all identifiers be fully qualified URIs,
however.
Reading Systems must trim all leading and trailing whitespace from the element value, as defined by the
XML specification [XML], before processing the value.
To determine whether an identifier conforms to an established system or has been granted by an
issuing authority, Reading Systems should parse the value of the property. For additional precision (e.g.,
if the scheme cannot be determined from the value or could lead to an ambiguous result), Authors may
attach an identifier-type property to assist in Reading System identification. When included, the
identifier-type property should take precedence over value parsing the identifier.
The following example shows how an identifier can be additionally marked as a DOI using the identifier-type
property.

  urn:doi:10.1016/j.iheduc.2008.03.001
   scheme="onix:codelist5">06
  …

This specification does not require or endorse the use of any specific scheme for identifiers, and imposes
no restrictions or requirements on identifier-type identifiers beyond those specified in the property
definition.
When an EPUB Publication is derived from another publication, the identifier for that source publication
may be included in the Publication metadata, and must be represented using the DCMES source
element.
› 3.4.4 The DCMES title Element
The [DCMES] title element represents an instance of a name given to the EPUB Publication.
Element Name
dc:title
Namespace
http://purl.org/dc/elements/1.1/
Usage
Required child of metadata. Repeatable.
Attributes
id [optional]

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The ID [XML] of this element, which must be unique within the document scope.
xml:lang [optional]
Speci
...