Copyright © 1999-2023 International Digital Publishing Forum and World Wide Web Consortium. W3C® liability, trademark and permissive document license rules apply.
This vocabulary, a part of EPUB® 3, defines a set of properties relating to the description of structural semantics of written works.
This section describes the status of this document at the time of its publication. A list of current W3C publications and the latest revision of this technical report can be found in the W3C technical reports index at https://www.w3.org/TR/.
This document was published by the EPUB 3 Working Group as a Group Note using the Note track.
Group Notes are not endorsed by W3C nor its Members.
This is a draft document and may be updated, replaced or obsoleted by other documents at any time. It is inappropriate to cite this document as other than work in progress.
The W3C Patent Policy does not carry any licensing requirements or commitments on this document.
This document is governed by the 2 November 2021 W3C Process Document.
Structural semantics add additional meaning about the specific structural purpose an HTML (or SVG)
element plays. The epub:type
attribute [epub-33] is used to express domain-specific semantics in
EPUB content documents and media overlay documents [epub-33], with the structural
information it carries complementing the underlying vocabulary.
The applied semantics refine the meaning of their containing elements without changing their nature for
assistive technologies, as happens when using the similar role
attribute [html]. The attribute
does not enhance the accessibility of the content, in other words, only provides hints about the
purpose.
Semantic metadata enriches content for use in publishing workflows and for author-defined purposes. It also allows reading systems to learn more about the structure and content of a document (e.g., to enable skippability and escapability in media overlay documents).
The [epub-33] specification defines a method for adding structural semantics using the attribute
axis: instead of adding new elements, EPUB creators can append the epub:type
attribute to existing elements to add the desired semantics. This document defines a set of property
values, i.e., a vocabulary, that can be used for that purpose.
While the EPUB Structural Semantics vocabulary is generally host language agnostic, it has been constructed primarily to enable semantic inflection of elements in the HTML vocabulary.
The HTML usage context fields indicate contexts in HTML documents where the given property is considered relevant. EPUB creators may use the properties on HTML markup elements not specifically listed, but must ensure that the semantics they express represent a subset of the carrying element's semantics and do not attach an existing element's meaning to a semantically neutral element.
The DPUB-ARIA role fields indicate the [dpub-aria-1.0] roles that can
alternatively be used with the [html] role
attribute to improve accessibility. These
roles may have more restrictive usage contexts, however, so may not be valid wherever the
epub:type
attribute [epub-33] is used (e.g., roles are not allowed on the [html] body
element). Refer to [html-aria] for more information about where the roles are allowed.
When processing HTML documents, reading systems may ignore such non-compliant properties, unless their usage context is explicitly overridden or extended by the host specification.
The Usage details field, when present, identifies a specification that defines or utilizes the designated property. Authors are only required to follow these usage details if they are creating content that conforms to the specified specification, or if the rules apply to all EPUB publications. In all other cases, the properties may be used however needed.
Ancillary material occurring after the main content of a publication, such as indices, appendices, etc.
The main content of a publication.
A section that introduces the work, often consisting of a marketing image, the title, author, and publisher, and select quotes and reviews.
DPUB-ARIA role: doc-cover (only allowed on cover image tag)
Preliminary material to the main content of a publication, such as tables of contents, dedications, etc.
A major thematic section of content in a work.
DPUB-ARIA role: doc-chapter
A major structural division that may also appear as a substructure of a part (esp. in legislation).
A major sub-division of a chapter.
A major structural division in a work that contains a set of related sections dealing with a particular subject, narrative arc, or similar encapsulated theme.
DPUB-ARIA role: doc-part
A component of a collection.
Sections and components that typically occur in the publication bodymatter.
A short summary of the principle ideas, concepts, and conclusions of the work, or of a section or excerpt within it.
HTML usage context: section, grouping content
DPUB-ARIA role: doc-abstract
A closing statement from the author or a person of importance, typically providing insight into how the content came to be written, its significance, or related events that have transpired since its timeline.
HTML usage context: section, grouping content
DPUB-ARIA role: doc-afterword
A concluding section or statement that summarizes the work or wraps up the narrative.
HTML usage context: section, grouping content
DPUB-ARIA role: doc-conclusion
A quotation set at the start of the work or a section that establishes the theme or sets the mood.
HTML usage context: section, grouping content
DPUB-ARIA role: doc-epigraph
A concluding section of narrative that wraps up or comments on the actions and events of the work, typically from a future perspective.
HTML usage context: section, grouping content
DPUB-ARIA role: doc-epilogue
An introductory section that precedes the work, typically not written by the author of the work.
HTML usage context: section, grouping content
DPUB-ARIA role: doc-foreword
A preliminary section that typically introduces the scope or nature of the work.
HTML usage context: section, grouping content
DPUB-ARIA role: doc-introduction
A section in the beginning of the work, typically containing introductory and/or explanatory prose regarding the scope or nature of the work's content
HTML usage context: section, grouping content
An introductory section that precedes the work, typically written by the author of the work.
HTML usage context: section, grouping content
DPUB-ARIA role: doc-preface
An introductory section that sets the background to a work, typically part of the narrative.
HTML usage context: section, grouping content
DPUB-ARIA role: doc-prologue
A section of supplemental information located after the primary content that informs the content but is not central to it.
HTML usage context: sectioning content
DPUB-ARIA role: doc-appendix
A short section of production notes particular to the edition (e.g., describing the typeface used), often located at the end of a work.
HTML usage context: sectioning content, grouping content
DPUB-ARIA role: doc-colophon
A collection of credits.
HTML usage context: sectioning content, grouping content
DPUB-ARIA role: doc-credits
A collection of keywords.
HTML usage context: sectioning content, grouping content
A single reference to an external source in a bibliography. A biblioentry typically provides more detailed information than its reference(s) in the content (e.g., full title, author(s), publisher, publication date, etc.).
Required parent context: bibliography
HTML usage context: grouping content
DPUB-ARIA role: doc-biblioentry (Deprecated)
A list of external references cited in the work, which may be to print or digital sources.
HTML usage context: sectioning content
DPUB-ARIA role: doc-bibliography
A group of terms, each having an opposite or nearly opposite meaning from a headword or idiom.
Required ancestor context: dictentry
HTML usage context: flow content
Usage details: Antonym Groups [epub-dict-10]
A condensed dictionary entry designed for constrained lookup viewports.
Required parent context: dictentry
HTML usage context: aside
Usage details: The Condensed Entry [epub-dict-10]
The definition of a particular meaning of a headword or idiom.
Required ancestor context: dictentry
HTML usage context: flow content
Usage details: Definitions [epub-dict-10]
A dictionary entry.
Required parent context: dictionary
HTML usage context: article
Usage details: The Dictionary Entry [epub-dict-10]
A collection of dictionary entries.
Usage details: The Dictionary Container [epub-dict-10]
An explanation of the historical origin of a headword.
Required ancestor context: dictentry
HTML usage context: flow content
Usage details: Etymologies [epub-dict-10]
An illustration of the usage of a defined term or phrase.
Required ancestor context: dictentry
HTML usage context: flow content
Usage details: Examples [epub-dict-10]
Supplemental grammatical information related to the headword and modifying a part of speech or a particular meaning.
Required ancestor context: dictentry
HTML usage context: flow content
Usage details: Related Grammatical Information [epub-dict-10]
A defining instance of a phrase.
Required parent context: dictentry or phrase-group
HTML usage context: dfn
Usage details: Idioms [epub-dict-10]
The grammatical function of a headword.
Required ancestor context: dictentry
HTML usage context: flow content
Usage details: The Dictionary Container [epub-dict-10]
A list of part of speech groups in a dictionary entry.
Required ancestor context: dictentry
HTML usage context: ol
Usage details: Part of Speech Lists [epub-dict-10]
A unit that associates a part of speech with its related sense and phrase groups.
Required ancestor context: dictentry
HTML usage context: flow content
Usage details: Part of Speech Groups [epub-dict-10]
A phonetic transcription of the pronunciation of a headword or other component of a dictionary entry.
HTML usage context: flow content
Usage details: Phonetic Transcriptions [epub-dict-10]
A list of phrase groups in a dictionary entry.
Required ancestor context: dictentry
Usage details: Phrase Lists [epub-dict-10]
A unit for organizing information pertaining to an idiom or example.
Required ancestor context: dictentry
HTML usage context: flow content
Usage details: Phrase Groups [epub-dict-10]
A list of sense groups in a dictionary entry.
Required ancestor context: dictentry
HTML usage context: ol
Usage details: Sense Lists [epub-dict-10]
A unit for organizing information pertaining to a particular meaning of a headword or idiom.
Required ancestor context: dictentry
HTML usage context: flow content
Usage details: Sense Groups [epub-dict-10]
A group of terms, each having identical or similar meaning to a headword or idiom.
Required ancestor context: dictentry
HTML usage context: flow content
Usage details: Synonym Groups [epub-dict-10]
The translation of a particular meaning of a source language headword, idiom, or example into a target language.
Required ancestor context: dictentry
HTML usage context: flow content
Usage details: Translations [epub-dict-10]
Grammatical or usage information related to a translation.
Required ancestor context: tran
HTML usage context: flow content
Usage details: Translation-Related Information [epub-dict-10]
A brief dictionary of new, uncommon, or specialized terms used in the content.
HTML usage context: dl, sectioning content
DPUB-ARIA role: doc-glossary
Usage details: The Glossary Container [epub-dict-10]
The definition of a term in a glossary.
Required parent context: glossary
HTML usage context: The glossdef property is implied on dd elements within a dl element marked with the glossary property.
Usage details: Glossary Terms and Definitions [epub-dict-10]
A glossary term.
Required parent context: glossary
HTML usage context: The glossterm property is implied on dd elements within a dl element marked with the glossary property.
Usage details: Glossary Terms and Definitions [epub-dict-10]
A navigational aid that provides a detailed list of links to key subjects, names and other important topics covered in the work.
HTML usage context: sectioning content, body
Usage details: index property [epub-indexes-10]
DPUB-ARIA role: doc-index
Editorial note pertaining to a single entry.
Required parent context: index-entry
HTML usage context: flow content
Usage details: index-editor-note property [epub-indexes-10]
One term with any attendant subentries, locators, cross references, and/or editorial note.
Required parent context: index-entry-list
HTML usage context: li; this property is implied when parent ul is of type index-entry-list (implicit or explicit)
Usage details: index-entry property [epub-indexes-10]
Collection of consecutive main entries or subentries.
Required parent context: index-entry , index-group, and index
HTML usage context: ul; this property is implied when the ul has an ancestor of index except within index-headnotes
Usage details: index-entry-list property [epub-indexes-10]
Collection of consecutive main entries that share a common characteristic, for example the starting letter of the main entries.
Required parent context: index
HTML usage context: sectioning content
Usage details: index-group property [epub-indexes-10]
Narrative or other content to assist users in using the index.
Required parent context: index
HTML usage context: sectioning content, header
Usage details: index-headnotes property [epub-indexes-10]
List of symbols, abbreviations or special formatting used in the index, and their meanings.
Required parent context: index-headnotes
HTML usage context: sectioning content, dl
Usage details: index-legend property [epub-indexes-10]
A reference to an occurrence of the indexed content in the publication.
Required parent context: index-entry , index-locator-list , and index-locator-range
HTML usage context: a; this property is implied when parent context is index-locator-list or index-locator-range
Usage details: index-locator property [epub-indexes-10]
Collection of sequential locators or locator ranges.
Required parent context: index-entry
HTML usage context: ul
Usage details: index-locator-list property [epub-indexes-10]
A pair of locators that connects a term to a range of content rather than a single point.
Required parent context: index-locator-list and index-entry
HTML usage context: flow content
Usage details: index-locator-range property [epub-indexes-10]
Word, phrase, string, glyph, or image representing the indexable content.
Required parent context: index-xref-related , index-entry and index-xref-preferred
HTML usage context: phrasing content; typically span
Usage details: index-term property [epub-indexes-10]
Wrapper for a list of the term categories belonging to an index.
Required parent context: index-xref-related and index-xref-preferred
HTML usage context: a
Usage details: index-term-categories property [epub-indexes-10]
Word, phrase, string, glyph, or image representing a category of terms in the index.
Required parent context: index-xref-related and index-xref-preferred
HTML usage context: a
Usage details: index-term-category property [epub-indexes-10]
Reference from one term to one or more preferred terms or term categories in an index (analogous to "See xxx").
Required parent context: index-entry
HTML usage context: flow content
Usage details: index-xref-preferred property [epub-indexes-10]
Reference from one term to one or more related terms or term categories in an index (analogous to "See also xxx").
Required parent context: index-entry
HTML usage context: flow content
Usage details: index-xref-related property [epub-indexes-10]
Preliminary sections and components, typically occurring in the publication frontmatter.
A section or statement that acknowledges significant contributions by persons, organizations, governments, and other entities to the realization of the work.
HTML usage context: section, grouping content
DPUB-ARIA role: doc-acknowledgments
A list of contributors to the work.
HTML usage context: section, grouping content
The copyright page of the work.
HTML usage context: section, grouping content
An inscription at the front of the work, typically addressed in tribute to one or more persons close to the author.
HTML usage context: section, grouping content
DPUB-ARIA role: doc-dedication
A set of corrections discovered after initial publication of the work, sometimes referred to as corrigenda.
HTML usage context: section, aside, grouping content
DPUB-ARIA role: doc-errata
The half title page of the work.
HTML usage context: section, grouping content
A formal statement authorizing the publication of the work.
HTML usage context: section, grouping content
Information relating to the publication or distribution of the work.
HTML usage context: section, grouping content
Acknowledgments of previously published parts of the work, illustration credits, and permission to quote from copyrighted material.
HTML usage context: section, grouping content
A record of changes made to a work.
HTML usage context: section, grouping content
Marketing section used to list related publications.
HTML usage context: section, grouping content
The title page of the work.
HTML usage context: section, grouping content
A detailed analysis of a specific topic.
Inherits from: xhv:complementary
HTML usage context: sectioning content
Helpful information that clarifies some aspect of the content or assists in its comprehension.
Inherits from: xhv:complementary
HTML usage context: aside, phrasing content
Replaced by: tip
Content, both textual and graphical, that is offset in the margin.
Inherits from: xhv:complementary
HTML usage context: aside, phrasing content
Replaced by: aside
Notifies the user of consequences that might arise from an action or event. Examples include warnings, cautions and dangers.
HTML usage context: section, grouping content
DPUB-ARIA role: doc-notice
A distinctively placed or highlighted quotation from the current content designed to draw attention to a topic or highlight a key point.
Inherits from: xhv:complementary
HTML usage context: aside
DPUB-ARIA role: doc-pullquote
Secondary or supplementary content, typically formatted as an inset or box.
Inherits from: xhv:complementary
HTML usage context: aside
Replaced by: aside
Helpful information that clarifies some aspect of the content or assists in its comprehension.
Inherits from: xhv:complementary
HTML usage context: aside, phrasing content
DPUB-ARIA role: doc-tip
A warning.
HTML usage context: section, grouping content
Replaced by: notice
A structurally insignificant heading that does not contribute to the hierarchical structure of the work.
HTML usage context: flow content, typically p, div or span
The title of the work as displayed on the work's cover.
Inherits from: title
HTML usage context: heading content. This property should only appear once within the document scope.
The full title of the work, either simple, in which case it is identical to title, or compound, in which case it consists of a title and a subtitle.
Inherits from: title
Same as: http://purl.org/dc/terms/title
HTML usage context: heading content. This property should only appear once within the document scope.
The title appearing on the first page of a work or immediately before the text.
Inherits from: title
HTML usage context: heading content. This property should only appear once within the document scope.
The text label that precedes an ordinal in a component title (e.g., 'Chapter', 'Part', 'Figure', 'Table').
Inherits from: title
HTML usage context: Phrasing content descendants of heading content, li and figcaption
An ordinal specifier for a component in a sequence of components (e.g., '1', 'IV', 'B-1').
Inherits from: title
HTML usage context: Phrasing content descendants of heading content, li and figcaption
An explanatory or alternate title for the work, or a section or component within it.
Inherits from: title
HTML usage context: heading content, phrasing content descendants of heading content, paragraphs, divs
DPUB-ARIA role: doc-subtitle
The primary name of a document component, such as a list, table, or figure.
HTML usage context: heading content, phrasing content descendants of heading content.
An explicit designation or description of a learning objective or a reference to an explicit learning objective.
HTML usage context: flow content, phrasing content
A collection of learning-objectives.
HTML usage context: sectioning content, grouping content
The understanding or ability a student is expected to achieve as a result of a lesson or activity.
HTML usage context: flow content
A collection of learning-outcomes.
HTML usage context: sectioning content, grouping content
A resource provided to enhance learning, or a reference to such a resource.
HTML usage context: flow content
A collection of learning-resources.
HTML usage context: sectioning content, grouping content
A formal set of expectations or requirements typically issued by a government or a standards body.
HTML usage context: sectioning content, phrasing content
A collection of learning-standards.
HTML usage context: sectioning content, grouping content
The component of a self-assessment problem that provides the answer to the question.
HTML usage context: aside, grouping content
A collection of answers.
HTML usage context: sectioning content, grouping content
A test, quiz, or other activity that helps measure a student's understanding of what is being taught.
HTML usage context: sectioning content
A collection of assessments.
HTML usage context: sectioning content
Instruction to the reader based on the result of an assessment.
HTML usage context: grouping content, phrasing content
A problem that requires the reader to input a text answer to complete a sentence, statement or similar.
HTML usage context: aside, grouping content
A problem with a free-form solution.
HTML usage context: aside, grouping content
A problem that requires the reader to match the contents of one list with the corresponding items in another list.
HTML usage context: aside, grouping content
A problem with a set of potential answers to choose from ‒ some, all, or none of which may be correct.
HTML usage context: aside, grouping content
A review exercise or sample.
See also: practices
HTML usage context: aside, grouping content
A collection of practices.
HTML usage context: sectioning content
A section of content structured as a series of questions and answers, such as an interview or list of frequently asked questions.
HTML usage context: lists or sectioning content
DPUB-ARIA role: doc-qna
The component of a self-assessment problem that identifies the question to be solved.
HTML usage context: grouping content
A problem with either a true or false answer.
HTML usage context: aside, grouping content
An area in a comic panel that contains the words, spoken or thought, of a character.
HTML usage context: li
Usage details: EPUB Region-Based Navigation [epub-region-nav-10]
An individual frame, or drawing.
HTML usage context: li
Usage details: EPUB Region-Based Navigation [epub-region-nav-10]
A group of panels (e.g., a strip).
HTML usage context: li
Usage details: EPUB Region-Based Navigation [epub-region-nav-10]
An area of text in a comic panel that represents a sound.
HTML usage context: li
Usage details: EPUB Region-Based Navigation [epub-region-nav-10]
An area of text in a comic panel. Used to represent titles, narrative text, character dialogue (inside a balloon or not) and similar.
HTML usage context: li
Usage details: EPUB Region-Based Navigation [epub-region-nav-10]
Explanatory information about passages in the work.
Inherits from: xhv:complementary
HTML usage context: aside, phrasing content
Replaced by: Open Annotation in EPUB
One of a collection of notes that occur at the end of a work, or a section within it, that provides additional context to a referenced passage of text.
See also: endnotes
HTML usage context: On the aside element when identifying a single endnote, or on descendants of sectioning content when identifying individual endnotes in a group (refer to footnotes and endnotes).
DPUB-ARIA role: doc-endnote (Deprecated)
A collection of notes at the end of a work or a section within it.
See also: endnote
HTML usage context: sectioning content
DPUB-ARIA role: doc-endnotes
Ancillary information, such as a citation or commentary, that provides additional context to a referenced passage of text.
See also: footnotes
HTML usage context: On the aside element when identifying a single footnote, or on descendants of sectioning content when identifying individual footnotes in a group (refer to footnotes and endnotes).
DPUB-ARIA role: doc-footnote
A collection of footnotes.
See also: footnote
HTML usage context: sectioning content
A note. This property does not carry spatial positioning semantics, as do the footnote and endnote properties. It can be used to identify footnotes, endnotes, marginal notes, inline notes, and similar when legacy naming conventions are not desired.
HTML usage context: On the aside element when identifying a single note, or on descendants of sectioning content when identifying individual notes in a group (refer to footnotes and endnotes).
A note appearing in the rear (backmatter) of the work, or at the end of a section.
See also: rearnotes
HTML usage context: On the aside element when identifying a single rearnote, or on descendants of sectioning content when identifying individual rearnotes in a group (refer to footnotes and rearnotes).
Replaced by: endnote
A collection of notes appearing at the rear (backmatter) of the work, or at the end of a section.
See also: rearnote
HTML usage context: sectioning content
Replaced by: endnotes
A reference to an annotation.
Inherits from: xhv:link
See also: annotation
HTML usage context: a
Replaced by: Open Annotation in EPUB
A link that allows the user to return to a related location in the content (e.g., from a footnote to its reference or from a glossary definition to where a term is used).
Inherits from: xhv:link
HTML usage context: a
DPUB-ARIA role: doc-backlink
A reference to a bibliography entry.
Inherits from: xhv:link
HTML usage context: a
DPUB-ARIA role: doc-biblioref
A reference to a glossary definition.
Inherits from: xhv:link
HTML usage context: a
DPUB-ARIA role: doc-glossref
A reference to a note, typically appearing as a superscripted number or symbol in the main body of text.
Inherits from: xhv:link
See also: note
HTML usage context: a
DPUB-ARIA role: doc-noteref
Terms for describing components at the phrasing level.
A phrase or sentence serving as a concluding summary of the containing paragraph.
HTML usage context: phrasing content
An acknowledgment of the source of integrated content from third-party sources, such as photos. Typically identifies the creator, copyright, and any restrictions on reuse.
HTML usage context: phrasing content
DPUB-ARIA role: doc-credit
A key word or phrase.
HTML usage context: phrasing content
A phrase or sentence serving as an introductory summary of the containing paragraph.
HTML usage context: phrasing content
A navigational aid that provides a list of links to the pagebreaks in the content.
HTML usage context: sectioning content
DPUB-ARIA role: doc-pagelist
Usage details:
The page-list nav
Element [epub-33]
A separator denoting the position before which a break occurs between two contiguous pages in a statically paginated version of the content.
Page break locators are also commonly used to provide static markers in purely digital publications (i.e., where no statically paginated equivalent exists). These markers provide consistent navigation regardless of differences in font and screen size that can otherwise affect the dynamic pagination of the content.
EPUB creators must ensure the name of the page break is an end user-consumable page number that identifies the page that is beginning.
HTML usage context: phrasing and flow content, where the value of the carrying elements title attribute takes precedence over element content for the purposes of representing the pagebreak value
DPUB-ARIA role: doc-pagebreak
A structure containing data or content laid out in tabular form.
HTML usage context: Not Allowed
Media overlays usage context: Identifies a seq
or par
as an escapable or skippable table structure.
A row of data or content in a tabular structure.
HTML usage context: Not Allowed
Media overlays usage context: Identifies a seq
or par
as an escapable or skippable table row.
A single cell of tabular data or content.
HTML usage context: Not Allowed
Media overlays usage context: Identifies a seq
or par
as an escapable or skippable table cell.
A structure that contains an enumeration of related content items.
HTML usage context: Not Allowed
Media overlays usage context: Identifies a seq
or par
as an escapable or skippable list structure.
A single item in an enumeration.
HTML usage context: Not Allowed
Media overlays usage context: Identifies a seq
or par
as an escapable or skippable list item.
This section is non-normative.
The following members of the EPUB 3 Working Group contributed to the development of this specification: