This specification defines a general manifest format for expressing information about a digital publication. It uses [[schema.org]] metadata augmented to include various structural properties about publications, serialized in [[JSON-LD]], to enable interoperability between publishing formats while accommodating variances in the information that needs to be expressed.
This specification defines a general manifest format to describe publications. It does not attempt to constrain the nature of the publications that use the manifest. Rather, it is designed to be adaptable to the needs of specific areas of publishing, such as audiobook production, by specifying a modular approach for creating specializations.
This specification is also intended to facilitate different user agent architectures. While it is expected that traditional Web user agents (browsers) will be able to consume a publication manifest, this should not limit the capabilities of any other possible type of user agent (e.g., applications, whether standalone or running within a user agent, or even publications that include their own user interface).
This specification does not define how user agents are expected to render publications that use the manifest format.
A digital publication consists of a finite set of resources that represent its content. This extent is known as its bounds and is defined within its manifest — it is obtained from the union of resources listed in the default reading order and resource list.
The term digital publication refers to a publication authored in a format that uses a profile of the manifest.
The internal representation of a manifest is the data structure created by user agents when they process the manifest and remove all possible ambiguities and incorporate any missing values that can be inferred from another source.
It is possible for the information expressed in the manifest to be the equivalent of the internal representation created by user agents if there are no ambiguities or missing information.
A manifest represents structured information about a publication, such as informative metadata, a list of resources, and a default reading order.
For the purposes of this specification, non-empty is used to refer to an element, attribute or property whose text content or value consists of one or more characters after whitespace normalization, where whitespace normalization rules are defined per the host format.
Profiles are publication formats (e.g., audiobooks) that use the manifest format defined in this specification to describe their bounds and content. These formats can extend the core definition in this specification with profile-specific terms and/or new requirements.
Although profiles can differ in their structural and content requirements, such variances are restricted to maintain a high degree of predictabibility between formats. (See .)
A digital publication is described by its manifest, which provides a set of properties expressed using a specific shape of JSON-LD [[json-ld]] (a variant of JSON [[ecma-404]] for linked data).
The manifest is what enables user agents to understand the bounds of digital publication and the connection between its resources. It includes metadata that describes the digital publication, as a publication has an identity and nature beyond its constituent resources. The manifest also provides a list of all the resources that belong to the digital publication and a default reading order, which is how it connects resources into a single contiguous work.
The properties of the manifest describe the basic information a user agent requires to process and render a publication. For ease of understanding, these properties are categorized as follows:
Descriptive properties describe aspects of a digital publication, such as its title, creator, and language.
Resource categorization properties describe or identify common sets of resources, such as the resource list and default reading order. These properties refer to one or more resources, such as HTML documents, images, scripts, and metadata records.
The manifest also identifies key resources of a digital publication through the use of
link relations. These relations are applied to the rel property of LinkedResource
objects (e.g., the links found in the table of
contents and resource list).
The types of resources these relations identify are categorized as follows:
Informative resources are resources that contain additional information about the publication, such as its privacy policy, accessibility report, or preview.
Structural resources are key meta structures of the publication, such as the cover image, table of contents, and page list.
These categorizations have no relevance outside this specification (i.e., the properties are not actually grouped together in the manifest).
This specification defines the publication manifest as a specific "shape" of [[!json-ld]]. This means that the manifest SHOULD be expressed using only the syntactic constructions defined in this specification, as opposed to all the possibilities offered by the JSON-LD syntax.
This shape is also defined, informally, through a JSON schema [[json-schema]] that expresses the constraints defined in this specification. This schema is maintained at https://github.com/w3c/pub-manifest/blob/master/schema/publication.schema.json.
The publication manifest also has a number of authoring flexibilities and compact authoring expressions. For example, it is not always required that object types be explicitly authored, as these are automatically generated during processing when missing (see for more information). An internal representation of the manifest data is defined separately; see the separate section on for further details.
As a consequence, a user agent does not have to be a full JSON-LD processor. User agents only need to be able to read the manifest's specific shape and internalize the data.
Manifest properties, in particular those categorized as descriptive properties, are primarily drawn from schema.org and its hosted extensions [[!schema.org]]. As a consequence, these properties inherit their syntax and semantics from schema.org, making manifest authoring compatible with schema.org authoring.
When a manifest item corresponds to a schema.org property, its property definition identifies its mapping and includes the defining type (e.g., CreativeWork or Book) in parentheses.
Schema.org additionally includes a large number of properties that, though relevant for publishing, are not mentioned in this specification. These properties MAY be used in a manifest as this document defines only the minimal set of manifest items.
When using additional schema.org properties, ensure that they are valid for the type of publication specified in the manifest. Properties are often available in many schema.org types, as a result of the inheritance model used by the vocabulary, but not all properties are available for all types. For more detailed information about which types accept which properties, refer to [[!schema.org]].
More information about using additional schema.org properties is also available in and
The following properties MUST be set in the manifest:
The priority of all other properties and resource relations is OPTIONAL, but MAY be modified by implementations of the manifest format.
Some properties are implicitly required, as they are compiled from alternative information when not explicitly authored. See for more information.
Although a digital publication's manifest is authored as [[!json-ld]], a user agent processes this information into the internal representation, which can be in any language, in order to utilize the properties.
To simplify the manifest format for developers, this specification defines an abstract representation
of the data structures employed by the manifest using the Web Interface Definition Language (Web
IDL) [[!webidl-1]] — the PublicationManifest
dictionary.
This definition expresses the expected names, datatypes, and possible restrictions for each member of the manifest. Unlike a typical Web IDL definition, however, user agents are not expected to expose the information in the manifest as an API. The Web IDL language is chosen solely to provide an abstraction of the data model.
The required members of the PublicationManifest dictionary do not exactly match the required members of the manifest as user agents are
expected to compile information from other sources in the absence of an explicit declaration for
some properties (e.g., for the title and reading order).
It is not necessary to understand the Web IDL definition in order to create digital publications. Authoring requirements are defined in the following sections.
PublicationManifest Dictionary
dictionary PublicationManifest {
sequence<DOMString> type = "CreativeWork";
required sequence<DOMString> conformsTo;
DOMString id;
boolean abridged;
sequence<DOMString> accessMode;
sequence<DOMString> accessModeSufficient;
sequence<DOMString> accessibilityFeature;
sequence<DOMString> accessibilityHazard;
LocalizableString accessibilitySummary;
sequence<Entity> artist;
sequence<Entity> author;
sequence<Entity> colorist;
sequence<Entity> contributor;
sequence<Entity> creator;
sequence<Entity> editor;
sequence<Entity> illustrator;
sequence<Entity> inker;
sequence<Entity> letterer;
sequence<Entity> penciler;
sequence<Entity> publisher;
sequence<Entity> readBy;
sequence<Entity> translator;
sequence<DOMString> url;
DOMString duration;
TextDirection direction;
sequence<DOMString> inLanguage;
DOMString dateModified;
DOMString datePublished;
ProgressionDirection readingProgression = "ltr";
required sequence<LocalizableString> name;
required sequence<LinkedResource> readingOrder;
sequence<LinkedResource> resources;
sequence<LinkedResource> links;
};
enum TextDirection {
"ltr",
"rtl",
"auto"
};
enum ProgressionDirection {
"ltr",
"rtl"
};
LinkedResource Dictionary
dictionary LinkedResource {
required DOMString url;
DOMString encodingFormat;
sequence<LocalizableString> name;
LocalizableString description;
sequence<DOMString> rel;
DOMString integrity;
double length;
sequence<LinkedResource> alternate;
};
Entity Dictionary
dictionary Entity {
sequence<DOMString> type;
required sequence<LocalizableString> name;
DOMString id;
DOMString url;
sequence<DOMString> identifier;
};
LocalizableString Dictionary
dictionary LocalizableString {
required DOMString value;
DOMString language;
};
This section describes the categories of values that can be used with properties of the publication manifest.
When a manifest property expects a literal text string as its value — one that is not language-dependent, such as a code value or date — its value MUST be expressed as a [[!json]] string.
Literal values are not changed during processing of the manifest, unlike other values which might be, for example, converted to objects.
When a manifest property expects a number as its value, the value MUST be expressed as a [[!json]] number.
When a manifest property expects a boolean as its value, the
value MUST be expressed as an [[!ecmascript]] Boolean value
(true or false).
Various manifest properties are expected to be expressed as [[!json]] objects. Although the use of objects is usually recommended, the following sections identify cases where it is also acceptable to use string values that are interpreted as objects depending on the context. The exact mapping of text values to objects is part of the property or object definitions.
When a manifest property expects a localizable text string as its value, the value MUST be expressed either as:
LocalizableString.A single string value represents an implied object whose value property is the
string's text and whose language is determined from other information in the manifest.
A LocalizableString is a [[!json]] object consisting of the
following properties:
| Term | Description | Required Value | Value Type | [[!schema.org]] Mapping |
|---|---|---|---|---|
value
|
The value of the localizable string. REQUIRED. | Text. | Literal | (None) |
language
|
The language of the value. OPTIONAL. | A well-formed language tag [[!bcp47]]. | Literal | (None) |
{
"value" : "",
"language" : ""
}
When a manifest property expects an entity (i.e., an individual or organization responsible for the various aspects of creation), its value MUST be expressed either as:
Entity.A single string value represents an instance of an Entity object whose
name property is the string's text and whose type is assumed
to be Person [[!schema.org]].
An Entity is defined as an instance of either the [[!schema.org]] Person or Organization type with the
following minimal property set:
| Term | Description | Required Value | Value Type | [[!schema.org]] Mapping |
|---|---|---|---|---|
type
|
The type of creator. OPTIONAL | One or more Text. Sequence MUST include "Person" or
"Organization". |
Array of Literals | (None) |
name
|
Name of the creator. REQUIRED. | One or more Text. | Array of Localizable Strings |
name
|
id
|
A canonical identifier associated with the creator. OPTIONAL. | A URL record [[!url]]. | Identifier | (None) |
url
|
An address associated with the creator. OPTIONAL. | A valid URL string [[!url]]. | URL |
url
|
identifier
|
An identifier associated with the creator (e.g., ORCID). OPTIONAL. | One or more text(s). | Array of Literals |
identifier
|
Note that user agents MAY interpret a wider range of creator properties defined by Schema.org than the ones in the preceding table.
When a manifest property links to one or more resources, it MUST be expressed either as:
A string value represents an implied LinkedResource object whose
url property is set to the string value.
A LinkedResource object is defined as follows:
| Term | Description | Required Value | Value Type | [[!schema.org]] Mapping |
|---|---|---|---|---|
type
|
The type of resource. OPTIONAL | One or more Text. Sequence MUST include "LinkedResource". |
Array of Literals | (None) |
url
|
Location of the resource. REQUIRED. | A valid URL string [[!url]]. Refer to the property definitions that accept this type for additional restrictions. | URL |
url
|
encodingFormat
|
Media type of the resource (e.g., text/html). OPTIONAL. |
MIME Media Type [[!rfc2046]]. | Literal |
encodingFormat
|
name
|
Name of the item. OPTIONAL. | One or more Text items. | Array of Localizable Strings |
name
|
description
|
Description of the item. OPTIONAL. | Text. | Localizable String |
description
|
rel
|
The relation of the resource to the publication. OPTIONAL. |
One or more relations. The values are either the relevant relation terms of the IANA link registry [[!iana-link-relations]], or specially-defined URLs if no suitable link registry item exists. |
Array of Literals | (None) |
integrity
|
A cryptographic hashing of the resource that allows its integrity to be verified. OPTIONAL. | One or more whitespace-separated sets of integrity metadata [[!sri]]. The value MUST conform to the metadata definition [[!sri]]. Refer to [[!sri]] for the list of cryptographic hashing functions that user agents are expected to support. |
Literal | (None) |
length
|
The total length of a time-based media resource in (possibly fractional) seconds. OPTIONAL | Number | Number | (None) |
alternate
|
References to one or more reformulation(s) of the resource in alternative formats. When specified, Order is not significant. OPTIONAL One or more of:
The order of items is not significant. Non-HTML resources SHOULD be
expressed as |
One or more instances of |
Array of Linked Resources | (None) |
Although user agent support for the integrity property is OPTIONAL, user agents
that support cryptographic hashing comparisons using this property MUST do so in accordance
with [[!sri]].
{
"type" : "LinkedResource",
"url" : "chapter1.html",
"encodingFormat" : "text/html",
"name" : "Chapter 1 - Loomings",
"integrity" : "sha256-13AE04E21177BABEDFDE721577615A638341F963731EA936BBB8C3862F57CDFC"
}
{
"type" : "LinkedResource",
"url" : "chapter1.mp3",
"encodingFormat" : "audio/mpeg",
"name" : "Chapter 1 - Loomings",
"alternate" : [
"chapter1.html",
{
"type": "LinkedResource",
"url": "chapter1.json",
"encodingFormat": "application/vnd.wp-sync-media+json",
"length": 1669
}
]
}
A string value represents an implied LinkedResource object whose
url property is set to the string value.
{
…
"resources" : [
"datatypes.svg",
{
"type" : "LinkedResource",
"url" : "test-utf8.csv",
"encodingFormat" : "text/csv",
"name" : "Test Results",
"description" : "CSV file containing the full data set used."
},
{
"type" : "LinkedResource",
"url" : "terminology.html",
"encodingFormat" : "text/html",
"rel" : "glossary"
}
],
…
}
URLs are used to identify resources associated with a digital publication. When a property expects a URL value, it MUST be a valid URL string [[!url]].
Manifest URLs are restricted to only the http and https
schemes [[!url]].
In the case of relative-URL strings, these are resolved to absolute-URL strings using a base URL [[!url]].
The base URL for relative-URL strings is determined as follows:
By consequence, relative-URL strings in embedded manifests are resolved against the URL of the
document that references the manifest unless the document declares a base URL (i.e., in
a <base> element in its
header).
URLs allow for the usage of characters from Unicode following [[rfc3987]]. See the note in the HTML5 specification for further details.
Identifiers are used to refer to a digital publication and the entities reponsible for its creation in a persistent and unambiguous manner. URLs, URNs, DOIs, ISBNs, and PURLs are all examples of persistent identifiers frequently used in publishing.
Identifiers MUST be expressed as URL records [[!url]]
When a manifest property allows one or more value of their respective type (e.g., literal, object, or URL), these values are expressed as [[!json]] arrays. When a property value is a single element, however, the array syntax MAY be omitted.
A manifest MUST set its JSON-LD context [[!json-ld]] with the following two components, in the specified order:
https://schema.orghttps://www.w3.org/ns/pub-context{
"@context" : [
"https://schema.org",
"https://www.w3.org/ns/pub-context"
],
…
}
The publication context document adds features to the properties defined in Schema.org (e.g., the requirement for the creator property to be order preserving).
Although Schema.org is often referenced using the http URI scheme, the vocabulary is being migrated to use the
secure https scheme as its default. The use of https when referencing
Schema.org in the manifest is REQUIRED by this specification.
The context can be extended by including additional paramaters — such as the global language and direction declarations — in an object following the publication context.
{
"@context" : [
"https://schema.org",
"https://www.w3.org/ns/pub-context",
{
"language" : "es"
}
],
…
}
Each natural language property value in a manifest (e.g., title, creators) has a default natural language, which is the language that it is expressed in (e.g., English, French, Chinese). It also has a natural base direction in which it is written — the display direction, either left-to-right or right-to-left.
The digital publication manifest provides the ability to set both these concepts globally — and, for language, on individual items — to aid user agents in interpreting and presenting the metadata.
The default language for natural language manifest properties is set by including a global
language declaration in the context using the language keyword [[!json-ld]]. It is used to expand simple string
values into localizable strings during the processing of the manifest, as well as to provide a language
for localizable strings that omit one.
The value of language MUST be a well-formed language
tag [[!bcp47]].
The global language declaration, when present, MUST follow the publication context.
Unlike the default language, the default text direction cannot be specified in the context as
JSON-LD does not currently include facilities for this. As an interim measure, this
specification defines a direction property for defining the global text
direction.
| Term | Description | Required Value | Value Category | [[!schema.org]] Mapping |
|---|---|---|---|---|
direction
|
Default base direction for textual manifest values | One of: ltr, rtl, or auto. |
Literal | (None) |
The base language direction MUST have one of the following values:
ltr: indicates that the textual values are explicitly directionally
set to left-to-right text;rtl: indicates that the textual values are explicitly directionally
set to right-to-left text;auto: indicates that the textual values are explicitly directionally
set to the direction of the first character with a strong directionality, following the
rules of the Unicode Bidirectional Algorithm [[!bidi]].{
"@context" : [
"https://schema.org",
"https://www.w3.org/ns/pub-context",
{"language":"he"}
],
"direction" : "rtl"
}
Default values are not specified for the global language and base direction declarations.
It is possible to set the language locally for any natural language value in the manifest using a localizable string:
{
"@context" : [
"https://schema.org",
"https://www.w3.org/ns/pub-context",
{"language": "zh"}
],
"type" : "Book",
…
"author" : {
"type : "Person",
"name" : [
"孔子",
{
"value" : "Confucius",
"language" : "en"
}
]
}
}
The value of the language keyword [[!json-ld]] MUST be a well-formed language
tag [[!bcp47]].
A local language declaration takes precedence over a global declaration.
It is not possible to set the direction explicitly for a specific value. For more information, refer to .
A digital publication's
manifest defines its Publication Type using the type keyword [[!json-ld]]. The type
MAY be mapped onto any [[!schema.org]] type, but CreativeWork is assumed as the
default when no type is specified.
{
"@context" : ["https://schema.org", "https://www.w3.org/ns/pub-context"],
"type" : "CreativeWork",
…
}
More specific subtypes of CreativeWork, such as Article, Book, TechArticle, and Course can be used instead of, or in addition
to, CreativeWork.
{
"@context" : ["https://schema.org", "https://www.w3.org/ns/pub-context"],
"type" : "Book",
…
}
Each schema.org type defines a set of properties that are valid for use with it. To ensure that the manifest can be validated and processed by schema.org-aware processors, the manifest SHOULD contain only the properties associated with the selected type.
If properties from more than one type are needed, the manifest MAY include multiple type declarations.
{
"@context" : ["https://schema.org", "https://www.w3.org/ns/pub-context"],
"type" : ["Book", "VisualArtwork"],
…
}
User agents SHOULD NOT fail to process manifests that are not valid to their declared schema.org type(s).
Refer to the schema.org site for the complete list of CreativeWork
subtypes.
A digital publication indicates the profile its manifest and content are in conformance
with using the conformsTo property.
| Term | Description | Required Value | Value Type | [[!dcterms]] Mapping |
|---|---|---|---|---|
conformsTo
|
URL of the profile. | A valid URL string [[!url]]. | Array of URLs | conformsTo |
The URL to use for each profile is defined in its respective specification.
The conformsTo property can also be used to indicate conformance to other
specifications and standards (e.g., to [[WCAG21]]).
{
…
"conformsTo" : "https://www.w3.org/TR/audiobooks",
…
}
The abridged property provides information on whether or not a digital
publication has been shortened from its original form.
| Term | Description | Required Value | Value Type | [[!schema.org]] Mapping |
|---|---|---|---|---|
abridged
|
Indicates whether the book is an abridged edition. | Either true or false. |
Boolean |
abridged (Book) |
{
…
"abridged" : true,
…
}
The accessibility properties provide information about the suitability of a digital publication for consumption by users with different preferred reading modalities. These properties typically supplement an evaluation against established accessibility criteria, such as those provided in [[wcag21]].
The following properties are categorized as accessibility properties:
| Term | Description | Required Value | Value Category | [[!schema.org]] Mapping |
|---|---|---|---|---|
accessMode
|
The human sensory perceptual system or cognitive faculty through which a person may process or perceive information. | One or more text(s). | Array of Literals |
accessMode (CreativeWork) |
accessModeSufficient
|
A list of single or combined access modes that are sufficient to understand all the intellectual content of a resource. | One or more ItemList. | Array of Literals |
accessModeSufficient (CreativeWork) |
accessibilityFeature
|
Content features of the resource, such as accessible media, alternatives and supported enhancements for accessibility. | One or more text(s). | Array of Literals |
accessibilityFeature (CreativeWork) |
accessibilityHazard
|
A characteristic of the described resource that is physiologically dangerous to some users. | One or more text(s). | Array of Literals |
accessibilityHazard (CreativeWork) |
accessibilitySummary
|
A human-readable summary of specific accessibility features or deficiencies that is consistent with the other accessibility metadata. | Text. | Localizable String |
accessibilitySummary (CreativeWork) |
Detailed descriptions of these properties, including the expected values to use with them, are available at [[webschemas-a11y]].
A reference to a detailed accessibility report can also be provided if more information is needed than can be expressed by these properties.
{
…
"accessMode" : ["textual", "visual"],
"accessibilityFeature" : ["alternativeText", "longDescription"]
"accessModeSufficient" : [
{
"type" : "ItemList",
"itemListElement" : ["textual", "visual"]
},
{
"type" : "ItemList",
"itemListElement" : ["textual"]
}
],
…
}
An address is a URL that identifies the source location of a digital
publication. It is expressed using the url property.
| Term | Description | Required Value | Value Type | [[!schema.org]] Mapping |
|---|---|---|---|---|
url
|
URL of the publication. | A valid URL string [[!url]]. | Array of URLs |
url (Thing) |
A digital publication MAY have more than one address, but all the addresses MUST resolve to the same document.
{
…
"url" : "https://publisher.example.org/frankenstein",
…
}
A digital publication's
canonical identifier property provides a unique identifier for a digital
publication. It is expressed using the id property.
| Term | Description | Required Value | Value Type | [[!schema.org]] Mapping |
|---|---|---|---|---|
id
|
Preferred version of the publication. | A URL record [[!url]]. | Identifier | (None) |
Ensuring uniqueness of canonical identifiers is outside the scope of this specification. The actual achievable uniqueness depends on such factors as the conventions of the identifier scheme used and the degree of control over assignment of identifiers.
If a canonical identifier is not provided in the manifest, or the value is an invalid URL, the digital publication does not have a canonical identifier. User agents MUST NOT attempt to construct a canonical identifier from any other identifiers provided in the manifest.
The specification of the canonical identifier MAY be complemented by the inclusion of
additional types of identifiers using the identifier property [[!schema.org]] and/or its subtypes.
{
…
"id" : "http://www.w3.org/TR/tabular-data-model/",
"url" : "http://www.w3.org/TR/2015/REC-tabular-data-model-20151217/",
…
}
{
…
"id" : "urn:isbn:9780123456789",
"url" : "https://publisher.example.org/wuthering-heights",
…
}
A creator is an individual or organization responsible for the creation of a digital publication.
The following properties are categorized as creators:
| Term | Description | Required Value | Value Category | [[!schema.org]] Mapping |
|---|---|---|---|---|
artist
|
The primary artist for the publication, in a medium other than pencils or digital line art. | One or more Person. |
Array of Entities |
artist (VisualArtwork) |
author
|
The author of the publication. | One or more Person and/or
Organization. |
Array of Entities |
author (CreativeWork) |
colorist
|
The individual who adds color to inked drawings. | One or more Person. |
Array of Entities |
colorist (VisualArtwork) |
contributor
|
Contributor whose role does not fit to one of the other roles in this table. | One or more Person and/or
Organization. |
Array of Entities |
contributor (CreativeWork) |
creator
|
The creator of the publication. | One or more Person and/or
Organization. |
Array of Entities |
creator (CreativeWork) |
editor
|
The editor of the publication. | One or more Person. |
Array of Entities |
editor (CreativeWork) |
illustrator
|
The illustrator of the publication. | One or more Person. |
Array of Entities |
illustrator (Book) |
inker
|
The individual who traces over the pencil drawings in ink. | One or more Person. |
Array of Entities |
inker (VisualArtwork) |
letterer
|
The individual who adds lettering, including speech balloons and sound effects, to artwork. | One or more Person. |
Array of Entities |
letterer (VisualArtwork) |
penciler
|
The individual who draws the primary narrative artwork. | One or more Person. |
Array of Entities |
penciler (VisualArtwork) |
publisher
|
The publisher of the publication. | One or more Person and/or
Organization. |
Array of Entities |
publisher (CreativeWork) |
readBy
|
A person who reads (performs) the publication (for audiobooks). | One or more Person. |
Array of Entities |
readBy (Audiobook) |
translator
|
The translator of the publication. | One or more Person and/or
Organization. |
Array of Entities |
translator (CreativeWork) |
Creators MUST be represented either as:
Person [[!schema.org]]; orPerson or Organization [[!schema.org]].A single string value is a shorthand for a [[!schema.org]] Person whose
name property is set to that string value. (See also .)
When compiling each set of creator information from a [[!schema.org]] Person or Organization type, user agents
MUST retain the properties defined for the Entity type, when
available.
The manifest MAY include more than one of each type of creator.
{
…
"url" : "https://publisher.example.org/alice-in-wonderland",
"author" : {
"type" : "Person",
"name" : "Lewis Carroll"
}
}
{
…
"author" : [
"Jeni Tennison",
{
"type" : "Person",
"name" : "Gregg Kellogg",
},
{
"type" : "Person",
"name" : "Ivan Herman",
"id" : "https://www.w3.org/People/Ivan/"
"identifier" : "0000-0003-0782-2704",
}
],
"editor" : [
"Jeni Tennison",
{
"type" : "Person",
"name" : "Gregg Kellogg",
}
],
"publisher" : {
"type" : "Organization",
"name" : "World Wide Web Consortium",
"id" : "https://www.w3.org/"
}
…
}
The global duration indicates the overall length of a time-based
digital publication (e.g., an audiobook or a book consisting of a series of video
clips). It is expressed using the duration property.
| Term | Description | Required Value | Value Category | [[!schema.org]] Mapping |
|---|---|---|---|---|
duration
|
Overall duration of a time-based publication. | Duration value as defined by [[!iso8601]]. | Literal |
duration (Property) |
{
…
"type" : "Audiobook",
"id" : "https://example.org/flatland-a-romance-of-many-dimensions/",
"url" : "https://w3c.github.io/pub-manifest/experiments/audiobook/",
"name" : "Flatland: A Romance of Many Dimensions",
…
"duration" : "PT15153S",
…
}
The relevant Wikiepedia page gives a concise description of the ISO duration syntax.
The last modification date is the date when a digital publication was last
updated (i.e., whenever changes were last made to any of the resources of the publication,
including the manifest). It is expressed using the dateModified
property.
| Term | Description | Required Value | Value Category | [[!schema.org]] Mapping |
|---|---|---|---|---|
dateModified
|
Last modification date of the publication. | A Date or DateTime
value [[!schema.org]], both expressed in ISO 8601 Date, or Date Time
formats, respectively [[!iso8601]]. |
Literal |
dateModified (CreativeWork) |
The last modification date does not necessarily reflect all changes to a publication (e.g., if a digital publication format allows references to third-party content). User agents SHOULD check the last modification date of individual resources to determine if they have changed and need updating.
{
…
"dateModified" : "2015-12-17",
…
}
The publication date is the date on which a digital publication was
originally published. It represents a static event in the lifecycle of a publication and
allows subsequent revisions to be identified and compared. It is expressed using the
datePublished property.
| Term | Description | Required Value | Value Category | [[!schema.org]] Mapping |
|---|---|---|---|---|
datePublished
|
Creation date of the publication. | A Date or DateTime, both expressed
in ISO 8601 Date, or Date Time formats, respectively [[!iso8601]]. |
Literal |
datePublished (CreativeWork) |
The exact moment of publication is intentionally left open to interpretation: it could be when the publication is first made available or could be a point in time before publication when the publication is considered final.
{
…
"datePublished" : "2015-12-17",
"dateModified" : "2016-01-30",
…
}
A digital publication has at least one natural language, which is the language that the content is expressed in (e.g., English, French, Chinese). The manifest includes the following property to set this concept, which can influence, for example, the behavior of a user agent (e.g., to preload a dictionary or text-to-speech engine).
| Term | Description | Required Value | Value Category | [[!schema.org]] Mapping |
|---|---|---|---|---|
inLanguage
|
Default language for the publication. | One or more well-formed language tags [[!bcp47]]. | Array of Literals |
inLanguage (Property) |
The natural language MUST be a well-formed language tag [[!bcp47]].
If a user agent requires the publication language and it is not available in the manifest, or the obtained value is not well-formed [[!bcp47]], the user agent MAY attempt to determine the publication language when generating its internal representation. This specification does not mandate how such a language tag is created. The user agent might:
If a user agent requires a primary language for the publication and more than one language is
specified, the first entry in the inLanguage array MUST be recognized as the
primary.
It is important to differentiate the language of the publication from the language of the individual resources that compose it. If such resources are, for example, in HTML, the language needs to be set in those resources, too. The language of the publication is not inherited.
The reading progression direction establishes the
reading direction from one resource to the next within a digital publication. It is
used to adapt such publication-level interactions as menu position, touch gestures, swap
direction, and tap zones for next and previous page. The reading progression is expressed
using the readingDirection property.
| Term | Description | Required Value | Value Category | [[!schema.org]] Mapping |
|---|---|---|---|---|
readingProgression
|
Reading progression direction from one resource to the other. | One of: ltr or rtl. |
Literal | (None) |
The value of this property MUST be either:
ltr: left-to-right;rtl: right-to-left.The default value is ltr. If the readingProgression is not set,
user agents MUST use the default value when generating their internal
representation.
This property has no effect on the rendering of the individual primary resources; it is only relevant for the progression direction from one resource to the other.
{
…
"readingProgression" : "ltr",
…
}
The title provides the human-readable name of a digital publication. It is expressed
using the name property.
| Term | Description | Required Value | Value Category | [[!schema.org]] Mapping |
|---|---|---|---|---|
name
|
Human-readable title of the publication. | One or more text items for the title. | Array of Localizable Strings |
name (Thing) |
If a title is not included in the manifest, and a digital publication does not define alternative rules for obtaining one, the user agent MUST create one. This specification does not specify what heuristics to use to generate such a title.
A user agent is not expected to produce a meaningful title [[wcag21]] for a publication when one is not specified.
{
…
"name" : "Heart of Darkness",
…
}
Publication resources are specified via the default reading order, the resource list, and the links, as defined in this section. These lists contain references to informative resources like the privacy policy, and structural resources like the table of contents.
Note that a particular resource's URL MUST NOT appear in more than one of these lists, and a URL MUST NOT be repeated within a list.
The manifest MUST NOT include a reference to itself within any of these lists.
The default reading order is a specific progression through a set of digital publication resources. A user might follow alternative pathways through the content, but in the absence of such interaction the default reading order defines the expected progression from one resource to the next.
The default reading order is expressed using the readingOrder property.
| Term | Description | Required Value | Value Category | [[!schema.org]] Mapping |
|---|---|---|---|---|
readingOrder
|
Order of progression through the resources of a digital publication. |
One or more |
Array of Linked Resources | (None) |
Each element of the readingOrder property MUST be expressed either as:
LinkedResource
object.A single string value represents an instance of a LinkedResource object whose
url property is the string's text.
The order of items is significant.
The URLs expressed in the reading order MUST NOT include fragment identifiers. Non-HTML
resources SHOULD be expressed as LinkedResource objects with their
encodingFormat values set.
The default reading order MUST include at least one resource.
{
…
"readingOrder" : [
"html/title.html",
"html/copyright.html",
"html/introduction.html",
"html/epigraph.html",
"html/c001.html",
…
],
…
}
{
…
"readingOrder" : [
{
"type" : "LinkedResource",
"url" : "html/title.html",
"encodingFormat" : "text/html",
"name" : "Title page"
},
{
"type" : "LinkedResource",
"url" : "html/copyright.html",
"encodingFormat" : "text/html",
"name" : "Copyright page"
},
…
],
…
}
The resource list enumerates any additional resources used in the processing or
rendering of a digital publication that are not already listed in the default
reading order. It is expressed using the resources property.
| Term | Description | Required Value | Value Category | [[!schema.org]] Mapping |
|---|---|---|---|---|
resources
|
List of additional publication resources used in the processing or rendering of a publication. |
One or more |
Array of Linked Resources | (None) |
Each element of the resources property MUST be expressed either as:
LinkedResource
object.A single string value represents an instance of a LinkedResource object whose
url property is the string's text.
The order of items is not significant.
The URLs MUST NOT include fragment identifiers. It is RECOMMENDED to use
LinkedResource objects with their encodingFormat values
set.
The completeness of the resource list can affect the usability of a digital publication in certain reading scenarios (e.g., the ability to read it offline). For this reason, it is strongly RECOMMENDED to provide a comprehensive list of all of the publication's constituent resources beyond those listed in the default reading order.
In some cases, a comprehensive list of these resources might not be easily achieved (e.g., third-party scripts that reference resources from deep within their source), but a user agent SHOULD still be able to render a publication even if some of these resources are not identified as belonging to the publication (e.g., if it is taken offline without them).
{
…
"resources" : [
"datatypes.html",
"datatypes.svg",
"datatypes.png",
"diff.html",
{
"type" : "LinkedResource",
"url" : "test-utf8.csv",
"encodingFormat" : "text/csv"
},
{
"type" : "LinkedResource",
"url" : "test-utf8-bom.csv",
"encodingFormat" : "text/csv"
},
…
],
…
}
The Links list is used to provide a list of resources that are not
required for the processing and rendering of a digital publication (i.e., the content
of the publication remains unaffected even if these resources are not available). Links are
expressed using the links property.
| Term | Description | Required Value | Value Category | [[!schema.org]] Mapping |
|---|---|---|---|---|
links
|
List of resources associated with a publication but not required for its processing or rendering. |
One or more |
Array of Linked Resources | (None) |
Each element of the links property MUST be expressed either as:
LinkedResource
object.A single string value represents an instance of a LinkedResource object whose
url property is the string's text.
The order of items is not significant.
It is RECOMMENDED to use LinkedResource objects with their
encodingFormat and rel values set.
Linked resources are typically made available to user agents to augment or enhance the processing or rendering, such as:
Links can also be used to identify resources used in the online rendering of a publication, but that are not essential to include when the publication is taken offline or packaged (e.g., to minimize the size). These include:
The links list SHOULD include resources necessary to render a linked resource
(e.g., scripts, images, style sheets).
Resources listed in the links list MUST NOT be listed in the default reading order or resource list.
User agents MAY ignore linked resources, and are not required to take them offline with a publication. These resources SHOULD NOT be included when packaging a publication.
The manifest is designed to provide a basic set of properties for use by user agents in presenting and rendering a digital publication, but MAY be extended in the following ways:
Although both methods are valid, the use of linked records is RECOMMENDED.
This specification does not define how such additional properties are compiled, stored or exposed by user agents in their internal representation of the manifest. A user agent MAY ignore some or all extended properties.
Extending the manifest through links to a record, such as an ONIX [[onix]] or
BibTeX [[bibtex]] file, MUST be expressed using a LinkedResource object, where:
rel value of the LinkedResource SHOULD include a relevant identifier defined by
IANA or by other organizations; if the link record contains descriptive metadata it MUST
include the describedby (IANA) identifier; encodingFormat in the link MUST use the MIME media
type [[!rfc2046]] defined for that particular type of record, if applicable.Linked records MUST be included in the resource list when they are part of the publication (i.e., are needed for more than just manifest extensibility). Otherwise, they MUST be included in the links list.
{
…
"links" : [
{
"type" : "LinkedResource",
"url" : "https://www.publisher.example.org/time-machine/onix.xml",
"encodingFormat" : "application/onix+xml",
"rel" : "describedby"
},
…
],
…
}
The application/onix+xml MIME type has not yet been registered by
IANA at the time of writing this document, and is included in the example for illustrative
purposes only.
Additional properties MAY be included directly in the manifest. It is RECOMMENDED that these properties be taken from public schemes like [[schema.org]] or [[dcterms]] and use values from controlled vocabularies whenever possible. Proprietary terms MAY be used, but it is RECOMMENDED that such terms be included using Compact IRIs [[!json-ld]], with prefixes defined as part of the context.
{
"@context" : [
"https://schema.org",
"https://www.w3.org/ns/pub-context",
{
"language" : "en",
"ex" : "https://example.org/vocab"
}
],
…
"ex:region" : "North America",
…
}
The schema.org context file [[schema.org]] defines a number of prefixes for commonly used vocabularies, such as the Dublin Core Terms (`dcterms`) [[dcterms]] and Element Set (`dc`) [[dc11]], the FOAF vocabulary (`foaf`) [[foaf]], and the Bibliographic Ontology (`bibo`) [[bibo]]. Properties from these vocabularies can be used without their prefixes having to be declared.
{
…
"copyrightYear" : "2015",
"copyrightHolder" : "World Wide Web Consortium",
…
}
{
…
"dcterms:subject" : ["Web data description languages","Data integration","Data Exchange"],
…
}
An accessibility report provides information about the suitability of a digital publication for consumption by users with varying preferred reading modalities. These reports typically identify the result of an evaluation against established accessibility criteria, such as those provided in [[wcag21]], and are an important source of information in determining the usability of a publication.
An accessibility report is identified using the accessibility-report link
relation.
The accessibility-report term is not currently registered in the
IANA link relations but the Working Group expects to add it.
The manifest SHOULD include a link to an accessibility report when one is available for a publication. It is RECOMMENDED that the report be included as a resource of the publication.
It is also RECOMMENDED that the accessibility report be provided in a human-readable format, such as HTML [[!html]]. Augmenting these reports with machine-processable metadata, such as provided in schema.org [[!schema.org]], is also RECOMMENDED.
{
…
"links" : [
{
"type" : "LinkedResource",
"url" : "https://www.publisher.example.org/sherlock-holmes-accessibility.html",
"rel" : "accessibility-report"
},
…
],
…
}
Not all digital publications will be available to all users (e.g., they might be restricted to registered users of a site). In such cases, the publisher might wish to provide a preview of the content in order to entice users to access the full version.
A preview is identified using the preview link
relation [[!iana-link-relations]].
Previews MAY be located externally or included as resources of digital publications.
{
…
"links" : [
{
"type" : "LinkedResource",
"url" : "preview.mp3",
"encodingFormat" : "audio/mpeg",
"rel" : "preview"
},
…
],
…
}
{
…
"links" : [
{
"type" : "LinkedResource",
"url" : "https://publisher.example.org/jekyll-hyde-preview.html",
"encodingFormat" : "text/html",
"rel" : "preview"
},
…
],
…
}
Users often have the legal right to know and control what information is collected about them, how such information is stored and for how long, whether it is personally identifiable, and how it can be expunged. Including a statement that addresses such privacy concerns is consequently an important part of publishing digital publications. Even if no information is collected, such a declaration increases the trust users have in the content.
A link to a privacy policy can be included in the manifest for this purposes. It is RECOMMENDED that the privacy policy be included as a resource of the publication.
A privacy policy is identified using the
privacy-policy link relation [[!iana-link-relations]].
{
…
"links" : [
{
"type" : "LinkedResource",
"url" : "https://www.w3.org/Consortium/Legal/privacy-statement-20140324",
"encodingFormat" : "text/html",
"rel" : "privacy-policy"
},
…
],
…
}
The cover is a resource that user agents can use to present a digital publication (e.g., in a library or bookshelf, or when initially loading the publication).
The cover is identified by the cover link relation. The URL expressed in the url term MUST NOT include a fragment
identifier.
The cover term is not currently registered in the IANA link
relations but the Working Group expects to add it.
If the cover is in an image format, a title and description SHOULD
be provided. User agents can use these properties to provide alternative text and
descriptions when necessary for accessibility.
More than one cover MAY be referenced from the manifest (e.g., to provide alternative formats and sizes for different device screens). If multiple covers are specified, each instance MUST define at least one unique property to allow user agents to determine its usability (e.g., a different format, height, width or relation).
{
…
"resources" : [
{
"type" : "LinkedResource",
"url" : "cover.html",
"encodingFormat" : "text/html",
"rel" : "cover"
},
…
],
…
}
{
…
"resources" : [
{
"type" : "LinkedResource",
"url" : "whale-image.jpg",
"encodingFormat" : "image/jpeg",
"rel" : "cover",
"name" : "Moby Dick attacking hunters",
"description" : "A white whale is seen surfacing from the water to attack a small whaling boat"
},
…
],
…
}
{
…
"resources" : [
{
"type" : "LinkedResource",
"url" : "lilliput.jpg",
"encodingFormat" : "image/jpeg",
"rel" : "cover"
},
{
"type" : "LinkedResource",
"url" : "lilliput.svg",
"encodingFormat" : "image/svg+xml",
"rel" : "cover"
},
…
],
…
}
The page list is a navigational aid that contains a list of static page demarcation points within a digital publication.
The page list is identified by the pagelist link relation. The URL expressed in the url term of the resource that
identifies the page list MUST NOT include a fragment identifier.
The pagelist term is not currently registered in the IANA link
relations but the Working Group expects to add it.
The link to the page list MUST NOT be specified in the links list.
{
…
"resources" : [
{
"type" : "LinkedResource",
"url" : "toc_file.html",
"rel" : "pagelist"
},
…
],
…
}
The table of contents is a navigational aid that provides links to the majort structural sections of a digital publication.
The table of contents is identified by the contents
link relation [[!iana-link-relations]]. The URL expressed in
the url term of the resource that identifies the table of contents MUST NOT
include a fragment identifier.
The link to the table of contents MUST NOT be specified in the links list.
The RECOMMENDED structure and processing model for the table of contents is defined in .
{
…
"resources" : [
{
"type" : "LinkedResource",
"url" : "toc_file.html",
"rel" : "contents"
},
…
],
…
}
If additional relations beyond those defined in this specification need to be expressed, the rel property can be extended in one of the
following ways:
Use of relations from [[!iana-relations]] is RECOMMENDED.
Links to the manifest MUST take one or both of the following forms:
An HTTP Link header field [[!rfc5988]] with its rel parameter
set to the value "publication".
Link: <https://example.com/webpub/manifest>; rel=publication
A link element [[!html]] with its rel attribute set to the
value "publication".
<link href="https://example.com/webpub/manifest" rel="publication"/>
When a manifest is embedded within an HTML document, the link MUST
include a fragment identifier that references the script element that contains the
manifest (see ).
<link href="#example_manifest" rel="publication">
…
<script id="example_manifest" type="application/ld+json">
{
"@context" : ["https://schema.org", "https://www.w3.org/ns/pub-context"],
…
}
</script>
When a digital publication format allows manifests to be embedded within an HTML document, the
manifest MUST be included in a script element [[!html]] whose type
attribute is set to application/ld+json [[!json-ld]].
<script type="application/ld+json">
{
"@context" : ["https://schema.org", "https://www.w3.org/ns/pub-context"],
…
}
</script>
Digital publication formats MAY define alternative methods of discovering a manifest that do no involve linking to, or embedding, a manifest (e.g., that manifest could be discovered through the use of a restricted name and/or location). This specification does not add any restrictions on such methods.
The steps for processing a manifest into its internal representation are given by the following algorithm.
The following error types are used in this algorithm:
User agents SHOULD NOT include in their internal representation any value that generates a validation error.
User agents SHOULD expose both validation and fatal errors, but this specification does not prescribe the manner in which this has to be done.
The algorithm takes the following arguments:
If successful, the algorithm returns an object containing the internal representation of the data.
This algorithm does not define how the manifest is discovered and obtained. The steps by which to do so are defined by each digital publication format.
For illustrative purposes, the examples in this section show the structure of internal representation as JavaScript objects. User agents can process and internalize the resulting structure in whatever language and form is appropriate.
Let processed be an object containing the internal representation of the manifest.
Let manifest be the result of parsing text as JSON [[!ecmascript]].
If parsing throws an error, this is a fatal error. Return failure.
If typeof(manifest) is not Object [[!ecmascript]], this is a
fatal error. Return failure.
() If manifest["@context"] does not contain the values
"https://schema.org" and "https://www.w3.org/ns/pub-context" (in
this order), this is a fatal error. Return failure.
() Determine the profile the manifest conforms to as follows:
The profile the publication conforms to is used to determine any additional extension steps that have to be performed during processing.
() Let lang be the value of the last instance
of the language keyword in an object in the manifest[@context] array. If
no instances of language exist, set lang to null.
If the value of lang is not a well-formed [[!bcp47]]
language tag, this is a validation error. Set lang to null.
The global language declaration obtained here is used to set the language for localizable strings without a declaration.
Iterate over each property term in manifest and expand its value, as necessary, as follows. More than one step MAY apply.
The steps below depend on the expected value category of a term. Care
should be taken that the value category may depend not only on the name of the term, but also on
the object it is used for. For example, the value category for the term url is an
Array (of URLs) when used for the PublicationManifest object, but a single URL
literal otherwise.
For this step, the variable current is set to the value of manifest[term] and is updated by each applicable transformation.
() If term expects an array but current contains a string or object value, convert current to an array and push value onto it.
A number of terms require their values to be arrays, but, for the sake of convenience, authors are allowed to use a single value instead of a one element array. For example,
{
…
"name" : "Et dukkehjem",
"author" : "Henrik Ibsen",
…
}
yields:
{
…
"name" : ["Et dukkehjem"],
"author" : ["Henrik Ibsen"],
…
}
() If term expects an entity but the value of current is a string str, convert current to an object with the following properties:
type – set to an array with the value
"Person";
name – set to str.
If typeof(current) is Array [[!ecmascript]], perform this
step on each element of the array.
Authors, editors, etc., are expected to be explicitly designed as an object of type
Person, but, for the sake of convenience, only their name has to be
specified. For example:
{
…
"author" : ["Ralph Ellison"],
…
}
This rule converts the string values to objects, yielding the following for the preceding example:
{
…
"author" : [
{
"type" : ["Person"],
"name" : "Ralph Ellison"
}
],
…
}
For simplicity, the conversion of name to a localizable string is described by a later step.
() If term expects a localizable string and current contains a string str, convert current to an object with the following properties:
value – set to str; and
language – set to the value of lang when not
null; otherwise, omitted.
If typeof(current) is Array [[!ecmascript]], perform this
step on each element of the array.
If typeof(current) is Object [[!ecmascript]], perform this
step on each property of the object.
Natural language text values are expected to be explicitly designed as localizable string objects, but, for the sake of convenience, can be simple strings. For example, if no language information has been provided via the global language declaration then:
{
"@context" : ["https://schema.org","https://www.w3.org/ns/pub-context"],
"name" : ["La Comédie humaine"],
…
}
yields:
{
"@context" : ["https://schema.org","https://www.w3.org/ns/pub-context"],
"name" : [
{
"value" : "La Comédie humaine"
}
],
…
}
If, however, an explicit language has been provided in the manifest, that language is added to the localizable string object. For example,
{
"@context" : [
"https://schema.org",
"https://www.w3.org/ns/pub-context",
{"language": "fr"}
],
"name" : ["La Comédie humaine"],
…
}
yields:
{
"@context" : [
"https://schema.org",
"https://www.w3.org/ns/pub-context",
{"language": "fr"}
],
"name" : [
{
"value" : "La Comédie humaine",
"language" : "fr"
}
],
…
}
() If term is a resource categorization property or
an alternate property, and any
value in the array in current is a string, convert each string str
to an object with the following properties:
LinkedResource"; andResource links are expected to be explicitly designed as an object of type
LinkedResource, but, for the sake of convenience, only their
absolute or relative URL has to be specified. For example,
{
…
"resources" : [
"css/book.css",
…
],
…
}
This step converts the string values to objects, yielding the following for the preceding example:
{
…
"resources" : [
{
"type" : ["LinkedResource"],
"url" : "css/book.css"
},
…
],
…
}
For simplicity, the conversion of relative paths to absolute is described by a later step.
() If term expects a URL and the value of current is a string that is not an absolute URL string, resolve the value using the value of base [[!rfc1808]].
If typeof(current) is Array [[!ecmascript]], perform this
step on each element of the array.
If typeof(current) is Object [[!ecmascript]], perform this
step on each property of the object.
All relative URLs in the publication manifest must be resolved against the base value to yield absolute URLs.
(, extension point) if a profile defines processing steps for profile-specific terms, those steps are executed at this point.
Set processed[term] to the value of current.
Add defaults from document for the following properties, when applicable:
() If processed["name"] is not set, or its value is an empty string:
Create a new object title:
if the title
element [[!html]] of document is set and its contains is
not empty, set title["value"] to the text content of the
title element and, if applicable, set
title["language"] to the language [[!html]].
otherwise, generate a value for title["value"] (see the separate note for details) and issue a validation error.
This step adds the content of the title element of document
when the name property is not specified in the manifest. For
example:
<html>
<head lang="en">
<title>The Golden Bough</title>
…
<script type="application/ld+json">
{
"@context" : ["https://schema.org","https://www.w3.org/ns/pub-context"],
…
}
</script>
yields:
{
…
"name" : [
{
"value" : "The Golden Bough",
"language" : "en"
}
],
…
}
() If processed["readingOrder"] is not set or its value is an empty string or array:
if document.URL is not set, this is a fatal error. Return failure.
otherwise, create an object and set its url property to the value of document.URL. Set processed["readingOrder"] to an empty array and add the object to it.
If the Digital Publication consists only of the referencing document, the default reading order can be omitted; it will consist, automatically, of that single resource.
If a profile specifies document fallbacks, those steps are executed at this point.
Perform data integrity checks on the following properties in processed:
() For each property with a known value type, check that the actual value matches the expected value. If not, this is a validation error.
() For each property term in processed that expects an array of entities, check whether each value entry in processed[term] has its name property set. If not, this is a validation error.
Repeat this step recursively for all properties of current that expect an object in which one or more properties expect entities.
( and ) Recursively check that every language property in processed is well-formed [[!bcp47]]. Each non well-formed value found is a validation error.
() If processed["direction"] is set and its value is not one of the required directional values, this is a validation error.
() If processed["type"] is not set or
contains an empty value, this is a validation error. Set its value to an array
with the value "CreativeWork".
() If processed["abridged"] is set and it is not a boolean value, this is a validation error.
() If processed["duration"] is set and its value is not a valid duration value, per [[!iso8601]], this is a validation error.
() If processed["dateModified"] is set and its value is not a valid date or date-time per [[!iso8601]], this is a validation error.
() If processed["datePublished"] is set and its value is not a valid date or date-time per [[!iso8601]], this is a validation error.
() If processed["inLanguage"] is set, check that each value in its array is well-formed [[!bcp47]]. Each non well-formed value found is a validation error.
() Verify processed["readingProgression"] as follows:
ltr".() For each resource categorization property term in processed, check whether each object P in processed[term] has P["url"] set:
If not, this is a validation error.
Otherwise, check whether P["url"] is a valid URL [[!url]]. If not, this is a validation error.
() For each property term in processed that expects type LinkedResource, if term["length"] is set and is not a valid number this is a validation error.
If a profile specifies data validation checks, those steps are executed at this point.
Return processed.
The manifest format defined in this specification is designed to be implemented and extended by publishing communities in the production of new profiles (e.g., audiobooks and scholarly publications). The flexibility the manifest format offers allows it to be tailored to each community's specific needs while also providing a common base for user agents that need to process the profiles (i.e., minimizing the differences between each profile and simplifying interoperability).
In order for a profile to be compatible with this specification, the following conditions MUST be met:
conformsTo property.Adding an example of a term added by, e.g., the audiobook profile would be a good idea, when available.
As the manifest is expressed using JSON-LD, the privacy and security considerations [[!json-ld]] detailed in that specification are applicable to all profiles of the manifest.
Some additional general considerations for profiles include:
More specific security and privacy considerations are left to each profile to detail, as these will vary depending on the nature of the digital publication format.
To facilitate navigation within pages and across sites, HTML uses the nav
element [[html]] to express lists of links. Although generic in nature by default, the
purpose of a nav element can be more specifically identified by use of the role
attribute [[html]]. In particular, the doc-toc role from the [[dpub-aria-1.0]]
vocabulary identifies the nav element as the digital publication's table of
contents.
Including an identifiable table of contents is an accessible way to produce any digital publication, but due to the flexibility of HTML markup, it also presents challenges for user agents trying to extract a meaningful hierarchy of links (e.g., to provide a custom view available from any page). To avoid duplicating the tables of contents for different uses, this section defines a syntax that is both human friendly and commonly used while still providing enough structure for user agent extraction.
Authors have a choice of lists (ordered or unordered) to construct their table of contents. By
tagging each link within these lists in anchor tags (a
elements), user agents can easily differentiate the information they need from any
peripheral content (asides) or stylistic tagging that has also been added. The table of contents can
consist of both active links (with an href attribute) and inactive links (excluding the
href attribute), providing additional flexibility in how the table of contents is
constructed (e.g., to omit links to certain headings or only link to certain content in a
preview).
The table of contents is expressed via an [[!html]] element (typically a nav element).
This element MUST be identified by the role attribute [[!html]] value
"doc-toc" [[!dpub-aria-1.0]], and MUST be the first element in the document in
document tree order [[!dom]]
with that role value.
The manifest SHOULD identify the resource that contains the table of contents.
Although the content model of the nav element is not restricted, user agents will only
be able to extract a usable table of contents when the following markup guidelines are followed:
Although a title for the table of contents is optional, to avoid having a user agent generate
a placeholder title when one is needed, it is advised to add one. Titles are specified using
any of the [[!html]] h1 through h6 elements. Note that only the first such
element is recognized as the title. If a heading element is not found before the list of links, user agents will assume that one has not been
specified.
The first [[!html]] ol or ul list element encountered in the nav element is assumed
to contain the list that defines the links into the content. This list will be found even if
it is nested inside of div elements, for example, as the algorithm ignores elements that are not relevant to its
processing. The list cannot occur inside of any skipped
elements, however, since their internal contents are not evaluated.
If the nav element does not contain one of these elements, then user agents will
not register the digital publication as containing a usable table of contents (e.g., a
machine-rendered option will not be available).
If the table of contents is considered as a tree of links, then each list item (li
element) inside of the list of links represents one
branch. Each of these branches has to have a name and optional destination in order to be
presented to users, and this information is obtained from the first a
element found within the list item, wherever it is
nested (again, excluding any a elements inside of skipped elements.)
The link destination for the branch is obtained from the a element's
href attribute, when specified. This attribute can be omitted if a link is
not available (e.g., in a preview) or not relevant (e.g., a grouping header). When providing
a link into the content, it is also possible to specify the relation of the linked document
(in a rel attribute) and the media type of the linked resource (in a
type attribute).
After finding the a element that labels the branch, user agents will continue to
inspect the markup for another list element (i.e., sub-branches). If a list is found, it is
similarly processed to extract its links, and so on, until there are no more nested branches
left to process.
A small set of elements are ignored when the parsing table of contents to avoid misinterpretation. These are the [[!html]] sectioning content elements and sectioning root elements. The reason they are ignored is because they can defined their own outlines (i.e., they can represent embedded content that is self-contained and not necessarily related to the structure of content links).
Any element that has its hidden
attribute set is also skipped, since hidden elements are not intended to be directly
accessed by users.
Although these elements can be included in the nav element, care has to be taken
not to embed important content within them (e.g., do not wrap a section element
around the list item that contains all the links into the content).
All elements that are not relevant to extracting the table of contents, and are not skipped, are ignored. Unlike skipped elements, ignoring means that user agents will continue to search inside them for relevant content, allowing greater flexibility in terms of the tagging that can be used.
This section defines an algorithm for extracting a table of contents from a nav element.
It is defined in terms of a walk over the nodes of a DOM tree, in tree order, with each node
being visited when it is entered and when it is exited during the walk. Each time
a node is visited, it can be seen as triggering an enter or exit event. In some
steps, user agents are provided a choice in how to process the content to provide flexibility for
different presentation models.
For illustrative purposes, the examples in this section show the structure of the table of contents as JavaScript objects. User agents can process and internalize the resulting structure in whatever language and form is appropriate.
For the purposes of this algorithm, a list element is defined as either an
[[!html]] ol or ul
element.
The following algorithm MUST be applied to a walk of a DOM subtree rooted at the first
nav element in document order with the role attribute value
doc-toc. All explanations are informative.
Let toc be a object that represents the table of contents and initialize it as follows:
name property for toc that represents the title of the
table of contents and set to an empty string.entries property for toc that represents all the
branches of the table of contents and set to an empty array.This step initializes the toc object that will store the title and the branches of the table of contents.
{
"name" : '',
"entries" : []
}
Initialize a stack.
The stack is used to hold branches that are not yet complete. As a new sub-branch is encountered, the parent gets pushed onto the stack so it can be retrieved later.
Let current toc branch be a variable set to null.
current toc branch is used to hold the object that represents the branch of the table of contents that is currently being processed.
Walk over the DOM in tree
order, starting with the nav element the table of contents is being
built from, and trigger the first relevant step below for each element as the walk enters
and exits it.
When entering a heading content element:
Run these steps:
If the stack is empty, and the name property of toc is
an empty string, set the name property to one of the
following:
If the resulting value of name is an empty string (e.g., after
removing any presentational elements and trimming all leading and trailing
whitespace), set the name property either to a placeholder
value or to null.
This step identifies the heading for the table of contents. A heading is only
processed if the value of the toc
name property is an empty string (i.e., no headings have yet been
encountered).
Whether a user agent sets the name to the descendant content of the
heading element, or generates a text string from it, depends on whether it will
re-use any descendant tagging in the presentation (e.g., to retain images,
MathML, ruby and other content that does not translate to text easily).
{
"name" : "Contents",
"entries" : []
}
If the name is not an empty string, or is null, then a
previous heading has already been encountered or content has been encountered
that indicates the nav element does not have a heading (e.g., a
list has already been processed, since the heading would not follow the list of
links).
{
"name" : null,
"entries" : []
}
If a heading is not specified, the user agent can provide its own for later use.
When entering a list element:
Run these steps:
If the name property of toc is an empty string, set
name to null.
If current toc branch is not null:
entries property of current toc branch is
null or a non-empty array, exit the element and
continue processing with the next element.null.Otherwise, if the stack is empty:
entries property of toc is
null or a non-empty array, exit the element and
continue processing with the next element.This algorithm does not process multiple lists in a single branch or at the root
of the nav element, so if a list has already been encountered (the
entries property contains one or more branches or is set to
null), this list is skipped.
If a list is encountered and the table of contents (toc) still does
not have a name (i.e., no heading element has been encountered), the table of
contents is assumed to not have a heading (i.e., the heading for the table of
contents cannot appear after the first list of entries). The value of the
name property is changed from an empty string to
null as no further headings encountered apply, either.
When exiting a list element:
If the stack is not empty, pop the top object off the stack and set current toc branch to it.
This resets current toc branch back to the parent object after all of its child branches have been processed.
When entering a list item element:
Run these steps:
name, url, type, and
rel properties for the object and set them to empty
strings.entries property for the object and set it to an empty
array.Each list item represents a possible new branch in the table of contents, so whenever one is encountered a new blank object is created in current toc branch.
{
"name" : '',
"url" : '',
"type" : '',
"rel" : '',
"entries" : []
}
This object gets populated with information as a descendant a
element and list are encountered.
When exiting a list item element:
Run these steps:
If entries property of current toc branch contains an
empty array, set its value to null.
If the stack contains one or more entries:
entries property of current toc branch
contains a non-empty array, and its name property is an
empty string, set its name to a placeholder value or
null;entries property of current toc branch
contains an empty array, and its name property is an empty
string, set current toc branch to null and exit this processing
step.Add current toc branch to the array in the entries
property of the object at the top of the stack.
Otherwise, add the object in current toc branch to the
entries array of toc.
Set current toc branch to null.
Exiting a list item indicates that processing of the current branch is complete.
Before adding this branch to its parent's entries array, the branch
needs to be tested to see if it has a name and/or any sub-branches. If it does
not have a name but has sub-branches, the branch is kept. The user agent can
either supply a placeholder value of its own creation or set the value to null.
If it does not have a name or any branches, it is invalid and is discarded.
To determine where to merge the branch, the stack is checked. If there are no
objects in the stack, it is added into the entries property of the
root toc object (i.e., it is a top-level branch). Otherwise, it gets
added into the entries property of the object immediately preceding
it in the stack.
As a final step, current toc branch is reset back to
null.
When entering an anchor element and current toc branch is not
null:
Run these steps:
If the name property of current toc branch is not an
empty string, do nothing.
Otherwise:
Set the name property of current toc branch to
one of the following:
If the resulting value of name is an empty string (e.g.,
after removing any presentational elements and trimming all leading
and trailing whitespace), set the name property to
null.
href attribute and the URL in the
attribute resolves to a resource in the default reading order or
resource list, set the url property of
current toc branch to the value. Otherwise, set the
property to null.type attribute, and the value of the
attribute is not an empty string after trimming leading and trailing
white space, set the type property of current toc
branch to its value. Otherwise, set the property to
null.rel attribute, and the value of the
attribute is not an empty string after trimming leading and trailing
white space, set the rel property of current toc
branch to its value. Otherwise, set the property to
null.Exit the element and continue processing with the next element.
This step processes anchor tags to obtain values for the name and
url properties of a branch.
If the name of the current branch is already defined, then processing of this element is terminated (i.e., to avoid processing multiple links for a single branch).
Whether a user agent sets the name of the entry to the descendant
content of the a element, or generates a text string from it,
depends on whether it will re-use any descendant tagging in the presentation
(e.g., to retain images, MathML, ruby and other content that does not translate
to text easily).
In addition to having an href attribute specified, it is necessary
that it resolve to a resource that belongs to the digital publication to meet
the requirements of this specification. If not, the branch is retained but the
entry will not be linkable.
Additional information about the target of the link — the type of resource and its relation — is also retained.
{
"name" : "In the Beginning",
"url" : "http://example.com/page1.svg",
"type" : "image/svg",
"rel" : null,
"entries" : []
},
When entering a sectioning content element, a sectioning root element, or an element with a hidden attribute:
Exit the element and continue processing with the next element.
As sectioning and sectioning root elements can define their own outlines, descending into them poses problems for generating the table of contents (i.e., they may contain content that is not directly related). As a result, they are skipped over when encountered to prevent their child content from being processed.
Otherwise: do nothing.
For all other elements, this steps allows their descendant elements to continue to be processed.
After completing the DOM walk, if the entries property of toc contains a non-empty array, toc represents the machine-processed table of contents.
Otherwise, the digital publication does not have a table of contents that can be used for machine rendering purposes.
If the entries array in the root toc object does not contain any
branches (either because no list was found in the nav element or the list
did not contain any conforming list items), then the algorithm did not produce a usable
table of contents.
The following is a manifest with a basic set of metadata for an example book profile.
A JSON encoding of the internal representation of this manifest is also available.
The following is a manifest for an example article profile. The article consists only of the document the manifest is embedded in. The title and reading order are omitted from the manifest, as these properties are automatically generated during processing from the title and URL of the containing document, respectively.
A JSON encoding of the internal representation of the manifest is also available, as well as a more elaborate version for the same document.
The following example shows a manifest that conforms to the Audiobooks profile [[audiobooks]].
A JSON encoding of the internal representation of this manifest is also available.
The following table identifies where manifest properties are defined and extended.
The following table identifies where the use of resource relations is defined.
| Name | Publication Manifest |
|---|---|
accessibility-report
|
|
contents
|
|
cover
|
|
pagelist
|
|
privacy-policy
|
|
preview
|