Web Publications Use Cases and Requirements

1.1 Terminology

• This document uses the term user agent, as used by the Web community; see, for example, the WAI glossary entry. The publishing community often uses the term “reading system” for roughly the same notion; while there may be subtle differences, it is better to stick to a single term for the purposes of this document.
• A Web Publication (WP) is a collection of one or more constituent resources, organized together in a uniquely identifiable grouping, and presented using standard Open Web Platform technologies.
• A Packaged Web Publication (PWP) is a Web Publication whose constituent resources are combined into a single distributable file, using some standard packaging format.
• In this document, manifest refers to an abstract means to contain information necessary to the proper management, rendering, and so on, of a publication. This is opposed to metadata that contains information on the content of the publication like author, publication date, and so on. The precise format of how such a manifest is stored is not considered in this document.

2.1 Open Web Platform

Req. 1: Web Publications should be able to make use of all features offered by the Open Web Platform (OWP).

There is a remarkable development of tools and frameworks built on top of OWP that make it possible to develop powerful interactive layers on top of OWP. These include, for example, data visualization systems (e.g., d3, built on top of SVG), possibilities to access external services like Wolfram Alpha, or tools to create and store (possibly as part of the publication) annotations. These tools have been traditionally developed around browsers and provide possibilities that publications should also benefit from. That requires that Web Publications become first class citizens on the Web platform.

• UC 1: A large, multidisciplinary, Web-based journal relies on traditional Web technologies like HTML and CSS for its content. The journal, responding to the evolving expectations of its audience, is increasingly using additional media such as video, audio, animated graphics, and very large images; the trend is to consider these as integral parts of the scientific output. The journal as a result needs access to the latest visualization and other data management tools that the OWP-based tools can offer.
• UC 2: Educational publications are increasingly making use of OWP features. In addition to video, audio, and animations, they may also include interactive exams (possibly linked to online evaluation facilities), visualization of data or of algorithms, and built-in interpreters for various languages (e.g., for courses on programming). In many respects, the borderline between these publications and Web applications is becoming fuzzy.
• UC 3: A large technology company with extensive “in-house” documentation to support technical and administrative processes and user documentation for their various products, develops all this material in digital-only formats. The quantity of documentation makes it impractical to produce these documents in print. Instead, the company publishes them on the company intranet, and/or provides them to their employees and contractors via specialized mobile applications. These documents, as a type of publication, require accessibility, portability of annotations, and the possible inclusion of complex media.
• UC 4: News outlets often rely on video, audio, large images, and interactive elements to enhance their content. Web Publications would allow news outlets to provide this content in a unique, identifiable format that can facilitate archiving and offline access.
• UC 5: Image-based narrative content like comics, manga, and graphic novels relies heavily on support for large images. This type of content may also experiment with interactivity and unique forms of navigation.

• Scope

2.2 Horizontal Dependencies

Req. 2: A Web Publication should conform to the requirements of all horizontal dependencies: accessibility, internationalization, device independence, security, and privacy.

Web content has to be consumed under different circumstances: it must be available to the largest possible audience in a secure manner, providing the necessary protection of the reader’s privacy. Publication content must be able to answer to a number of principles like accessibility, internationalization, device independence, security, and privacy. (These are usually referred to, in the W3C context, as “horizontal” dependencies.) These principles are, in general terms:

Accessibility:

People with disabilities should be able to access the content of a publication. They should be able to perceive, understand, navigate, and interact with it, as well as contribute to it. Accessibility encompasses all disabilities that affect access to the content, including visual, auditory, physical, speech, cognitive, and neurological disabilities.

Internationalization:

Publications should be well adapted to any language, writing systems, region, or culture. This includes the usage, when appropriate, of left-to-right, right-to-left, horizontal or vertical writing; item numbering, or interactive forms specific to local cultures; usage of the right character sets and of local typographic conventions.

Device Independence:

The content in a publication should be usable on a large number of devices with very different device characteristics: different screen types and sizes, various input modalities, varying level of processing power, etc. These different affordances should be automatic with no, or very little, user intervention.

Security:

Publications should be presented by a User Agent using a security model that is at least (if not more) secure than the standard Web security model. Doing this will prevent publications that contain malicious attacks, data theft, and other security incidents from impacting users by jeopardizing the integrity of the underlying data or machine operations.

Privacy:

The content in a publication should maintain and support user privacy, in spite of the fact that the evolution of online technologies has increased the possibility for the collection and processing of personal, and possibly sensitive, data. However, since a publication may use any part of the OWP, it may choose to use functionality such as the ability to track a user's activity within the publication.

These principles correspond to technical requirements on the underlying technologies (i.e., OWP, and its possible extension to Web Publications) insofar as the technologies must empower the authors (writers, editors, publishers, etc.) to produce content that follow them. Whether authors use the possibilities of these technologies or not is not addressed in this document.

All these constraints are formalized in the context of the usage on the Web and by extension Web Publications. This means that they are valid for publications in general. In some cases, for example due to legislative reasons, the demands on publications may be more stringent than for generic Web sites. The use cases below provide some examples for the publication-specific situations. Note also that some aspect of horizontal dependencies (e.g., accessibility or security), are also the subject of further use cases and requirements elsewhere in this document.

• UC 6: (On Accessibility) Legal Publishing Ltd. publishes all the official texts as issued by the government of its country. Per local legislation, the publication must be accessible, following W3C’s WCAG Level AA requirements, to serve as official references in courts.
• UC 7: (On Privacy, Accessibility) EducationPublishing Ltd. publishes digital textbooks to cover BigUniversity’s curriculae. These (digital) educational publications also include access to interactive tests via specialized services on the Web that regularly access the student’s progress. The privacy and the integrity of the student’s test data must be preserved. This, and the fact that digital textbooks must also abide to WCAG Level AA requirement in terms of accessibility, are such that EducationPublishing may be liable in case they are not fulfilled.
• UC 8: (On Internationalization) PublicationInternational SA. publishes literary work all over the world and in many languages. In order to continue its business in different countries, it must be able to produce digital publications acceptable by local customers. Vertical, right-to-left, and bidirectional writing, among other typesetting traditions, must be supported by the reading systems and possible to enable in the Web Publications. Additionally, the reading system should allow for varied interaction with the content, such as right-to-left page navigation for content in languages like Japanese and Arabic.
• UC 9: (On Privacy) Thomas has written a pamphlet advocating a government overthrow. The government has decreed that the author of the pamphlet as well as the readers of the pamphlet shall be jailed. Thomas needs to distribute the pamphlet in ways that preserve his anonymity and allow the public to read without fear of the government cyber-police.
• UC 10: (On Device Independence) Yoshio usually reads a book on his tablet when he is at home, but he does not carry his tablet around while commuting on the train. Instead, he prefers to use his phone to continue reading. Publications must be able to adapt to the consumption environment, so as to provide a good reading experience regardless of the device.
• UC 11: (On Security) LocalLibrary receives publications from a variety of sources that they then make available to their members. It is imperative that none of these publications can cause any damage to their own systems or those of their members.

• Accessibility
• Language and Base Direction
• Item-specific Language
• Reading Progression Direction
• Accessibility Report
• Privacy Policy

2.3 Escalating Trust

Req. 3: User agents may provide a method for escalating trust for a specific publication.

Some publications may require additional capabilities (for example, access to camera or geolocation) that a user agent might normally not enable. Today, some platform and UA vendors offer methods for otherwise untrusted local scripts to become trusted and regain API privileges, a similar ability needs to exist for publications as well.

• UC 12: Rebecca has assigned an exercise from a WP textbook. The exercise requires the use of geolocation to measure distances from the user’s location to a target. The UA detects that the WP came from a trusted source (the textbook publisher), and therefore allows the WP to use the full capabilities of the UA.

• Privacy Policy

3.1 Identification

Req. 4: A Web Publication, as a collection of resources, must be identified by either a single URL or a unique handle that can resolve to a single URL.

The unique identification of a specific Web Publication is essential. If not expressed as a URL, there should be a way to map this unique identification onto a Web Address. The Web Publication must be identifiable as a single logical resource with its own URL beyond the references to its constituent resources.

• UC 13: Scholarly references demand a unique identification of the publication and, possibly, its internal structure. That unique identification must be available as a Web link, to make it possible for other publications and other sites (e.g., the authors’ institutional sites) to unambiguously link to the publication. These features are essential in the scholarly community to make, for example, the assessment of individual researchers possible.
• UC 14: Textbook editions should be clearly distinct from one another using unique identifiers. Links should be accurate in order to avoid confusion in classes, especially since each class is not necessarily using the latest edition.
• UC 15: Marwin wants to search for a term on the publication. As a reader, he does not know the internal structure of the book, i.e., whether the content is one or several HTML files; he wants to search to be executed on the whole (logical) content, regardless of its internal representation.
• UC 16: Svetlana sets her preferences in terms of font selection and size, background color, etc, for her WP textbook. She wants those to be in effect on all chapters of the book automatically.
• UC 17: User agents that support value counters (page counters, section numbering, footnotes, endnotes), should do so across the entire Web Publication (as opposed to individual components being numbered separately)
• UC 18: Assistive Technology such as screen readers or voice dictation control needs to have the Web Publication presented to it as if it was a single unit.

• Web Publication Bounds
• Resources
• Primary Entry Page
• Address
• Canonical Identifier
• Linked Records
• Obtaining a Manifest
• Publication Types

Req. 5: All constituent resources, and their contents, should be identified by either a URL or a unique handle that can resolve to a URL.

The requirement that a Web Publication be uniquely identifiable can be easily extended to the constituents of a Web Publication, as well as the fragments, parts, sections, etc, of those resources. Those idenfications should be stable and resilient to changes and new iterations of the publication.

• UC 19: Markus refers to a specific mathematical theorem in a publication. That reference must be unique, stable and retrievable on the Web, and it should not depend on whether the publisher issues a new iteration of the target publication (thereby possibly change the section numbering).
• UC 20: Tanya and Kelly are collaborating on curriculum for the upcoming school year. They are able to reference the same Web Publication in their shared documents and rely on stable, retrievable links to sections within the WP.
• UC 21: Judit uses an annotation tool to comment on a publication authored by Pablo. She puts an annotation against a sentence in a particular paragraph, anchoring that annotation to the sentence using a reliable way of identifying it. That identification should not be invalidated by a subsequent change of the document by Pablo (unless he, e.g., removes that sentence).

• Embedding a Manifest
• Linking to a Manifest
• Page List
• Address
• Resource Categorization Properties
• Resource List
• Cover
• Table of Contents

3.2 Metadata

Req. 6: Web Publications should include technical metadata and descriptive metadata, including accessibility metadata, as well as any additional characteristics of the constituent resources.

A user agent may require information about the publication and its components in order to process it. For example, performance and memory requirements may prevent a user agent from parsing a large number of content documents in order to discover the necessary components and their relationships. A user agent may need to make some decisions about how to present content before displaying it.

A Web Publication should be able to include additional information that the user agent can use, such as:

• the rights of various components identified in the package;
• captions belonging to multimedia resources within the publication;
• whether there is a need for additional processing, such as with MathML;
• the title, author(s), cover image, etc., to display the publication on a shelf without downloading all its content;

• UC 22: Marla is writing an art book and wishes to include the rights relevant to the image of the Mona Lisa owned by the Louvre, so that a user agent will know whether it is permissible to download the image for offline use.
• UC 23: While listening to a chapter in an audiobook via a user agent with a display, Clarence would like to see the current chapter name displayed.
• UC 24: While listening to a chapter in an audiobook via a user agent with no display, Zara wants to see what chapter she is in by saying, “Hey [Digital Assistant], what’s this chapter called?” and then hear the name of the chapter before resuming reading.
• UC 25: Ferdous wants to buy a book about a museum exhibit, but before he does that, he wants to guarantee that the images and videos about the exhibits have detailed descriptions to ensure that he will be able to read it with a screen reader or refreshable Braille display. This can be done because the publisher provided that information as part of the metadata assigned to the Web Publication.
• UC 26: A university professor is developing a course and the professor knows that he is required by the university's policy to use digital materials that conform to WCAG 2.0 level AA. The professor searches to determine which titles are accessible and therefore suitable for his use. This can be done because the publishers have added Schema.org Accessibility Metadata to the Web Publication, describing the accessibility characteristics for each constituent resource.
• UC 27: When Bella is listening to an audiobook or browsing her digital bookshelf, she wants to ask questions like, “Hey [Digital Assistant], who’s the narrator?” or “How long is that book?” and hear the corresponding metadata read to her by text-to-speech before resuming listening to content or browsing.
• UC 28: Marco is an Ainu audiobook listener, and the book he is reading has a table of contents consisting of images because the Ainu language has no script. While listening, he asks for the chapter name, and the reading system plays the audio for the title of the current table of contents item, and then resumes playback from the last position in the content.
• UC 29: A library wants to promote a particular type of publication depending on different categories available in a publication’s metadata (age suitability, genre, author, etc.)
• UC 30: An online literary magazine wishes to compile an anthology of short stories authored by a specific writer. The magazine should be able to identify the stories within the manifests by author and bring those chapters together into a new Web Publication.

• Linking to a Manifest
• Accessibility
• Creators
• Language and Base Direction
• Item-specific Language
• Title
• Links
• Accessibility Report
• Privacy Policy
• Cover
• Table of Contents
• Linked records
• Obtaining a manifest

3.3 Resources

Req. 7: The information regarding the constituent resources of a Web Publication must be easily discovered and there should be a way to differentiate between essential and non-essential resources.

A Web Publication will likely be composed of multiple Web documents and their resources. A more complicated Web Publication may have many resources, some of which are essential and some of which are not. Because of this complexity, extracting in advance all the references to some or all constituent resources may be prohibitive. It is therefore necessary for the user agent to have an easy access to the list of constituent resources and some of their characteristics, such as media type, size, and whether they are essential.

In a publication, some content is essential to the user being able to consume it while other content could be either absent or have a provided fallback for situations such as limited connectivity or storage. This information, provided by the author or publisher of the Web Publication, would enable a user agent to provide a better experience to the user. For example, the user agent can ensure that essential resources are made available when offline (see § 4.5 Offline).

• UC 31: Nick is reading a long-form narrative on a device with limited storage: a publication filled with text, images, audio, and multimedia files. Nick also rides the subway where he loses Internet connectivity frequently and without warning for long stretches of time. During offline or low-storage situations, there are still critical parts of the publication that are consumable, mainly the text (and possibly images). Having a reasonable fallback for video, such as a poster image or placeholder image, would allow Nick to read the content while offline or on a device with limited storage.
• UC 32: Henry creates a Web Publication and includes the accessibility metadata indicating that the publication has descriptions for videos. He marks the accessible descriptions as essential and marks videos as non-essential while providing images as fall-back. This enables the print-disabled readers to access the accessible descriptions and video when there is good internet connectivity, and fall-back images along with accessible descriptions when internet connectivity is not optimum.
• UC 33: Gösta is reading a treatise on the theory of functions. A mathematical font is essential for the proper display of the mathematical formula in this publication, so the author has marked the font as essential so it is made available offline.
• UC 34: While reading an article on a new spam analysis algorithm, Lars is primarily interested in the findings of the research. Since the research was funded by a government agency, the dataset, consisting of millions of anonymized log files, is also available. Because of its size, the researchers have marked the dataset as non-essential for conveying the results of the paper and therefore indicates it can be skipped when reading the publication offline.
• UC 35: Sarah is reading a publication about the stock exchange. The current value of the stock is fetched (from a remote resource) when she opens the publication. However, when she is on the train (without a connection) one week later and opens the stock exchange publication, she will continue to see the value of the stock as it was the last time she opened the publication. It should be possible for either the content itself or the user agent to provide some user experience that notifies her that the currently presented data is a week old.
• UC 36: Risha publishes an article which includes an interactive component that accesses a database, exposed to the Web via a RESTful API. The interactive component is implemented as a JavaScript library. Such data cannot be included in a packaged publication and the interactive module is of no use without such data. Risha therefore marks the Web Publication component relative to the interactive module as not essential when offline.
• UC 37: Chiara is listening to an audiobook on Roman history. The description when she bought it mentioned that the maps and images referred to the book were available as supplemental content in the file. At the end of the audiobook, she is able to view the content, which helps her understand the audiobook better, but it is marked as non-essential if the audiobook is taken offline.
• UC 38: Stephanie, a student, is answering questions in an assessment embedded in a Web Publication. Her internet connection is unreliable at home. She should be able to save those responses in the Web Publication. The assessment allows her to submit responses to a database. A notification within the Web Publication should inform her whether the data has been successfully submitted.

• Embedding a Manifest
• Linking to a Manifest
• Address
• Resource Categorization Properties
• Links
• Cover
• Table of Contents

3.4 Default Reading Order

Req. 8: There should be a means to indicate the author’s preferred navigation structure among the resources of a Web Publication, and User Agents should provide an accessible way of navigating the same.

• UC 39: Moby Dick contains 136 chapters. Each chapter is a separate HTML document, with a logical order for reading them. It should be possible for the publication to inform the user agent that the proper order for consumption of the HTML documents is sequentially, starting by the first chapter.
• UC 40: The Encyclopedia of Stuff includes 1348 articles, each one in a unique HTML document. The publication must be able to indicate to the user agent that the standard way to consume the articles is alphabetical order, by title.
• UC 41: The third edition of the Writing Handbook has 10 chapters with 5-10 subsections apiece and 4-8 readings. Each subsection and reading starts its own HTML page. The Web Publication should be able to inform the user agent that the proper order for consumption of the HTML documents is sequentially, starting with the first chapter. Moreover, in the navigation structure, the user agent should be able to indicate to the user which subheadings and readings belong to which chapter, and that those subheadings and readings are navigated sequentially, starting with the first subheading in the parent chapter.

• Page List
• Default Reading Order
• Table of Contents

3.5 Navigation

Req. 9: A user agent should be able to reveal the navigable structure of a Web Publication as a table of contents that is accessible to users, including those with disabilities.

The table of contents must include a link to at least one resource, and all links should refer to resources within the publication bounds. The user agent presents an accessible table of contents, which allows the user to access the links without navigating away from the current resource.

• UC 42: Chandrasekhar has been assigned a set of exercises in his math Web Publication textbook. To double check his work, he wants to easily navigate to the answers in the back of the Web Publication. Using the table of contents exposable by his user agent, he is able to navigate to the answers and return to the exercise with ease.
• UC 43: Penelope has opened her Web Publication to its preface. She would like to skip the preface and go to chapter one. She is able to reveal the table of contents built into her Web Publication via a function in her user agent and view a link to chapter one. She changes her mind and decides to read the preface. Since she is still on the preface and has not navigated away, she only needs to close out of the table of contents to continue reading the preface.
• UC 44: Matilda is reading an anthology but would like to read her favorite author's short stories first. She is able to reveal the navigation built into her Web Publication via a function in her user agent and access the relevant stories.

• Table of Contents

Req. 10: For content that requires a player interface for time-based media, the Web Publication should provide the User Agent a way to navigate to a specific position in the content.

• UC 45: Belinda would like to skip directly to a specific short story in a collected edition. The Web Publication provides the user agent with metadata to access the short story.
• UC 46: Mr. Sterling asks his students to skip directly to the 23rd minute of an audiobook.
• UC 47: Ken was assigned part of a non-fiction book for a class. He wants to open the audiobook but only needs to listen to chapter 19. The Web Publication provides the user agent with metadata to access the chapter.

• Audiobook
• Table of Contents

3.6 Random Access to Content

Req. 11: Authors of a Web Publication should be able to provide the user agent with information to access random parts of the publication.

It should be possible for the author to convey several potential reading orders that may go beyond the “default” for the content of the publication. This alternative reading order may only include specific parts of the publication rather than the full content of the publication.

A user agent should be able to access the resources of the publication in whatever order it chooses—beyond the order provided by the publication itself.

• UC 48: EsteemedJournalPublisher would like to offer the users of the EsteemedJournal of Chemistry App the opportunity to read only the abstracts of the journals in the app. The publication would therefore provide the user a list (table of contents) of abstracts (disjointed objects in the package with semantic information or metadata informing the package of the nature of the object).
• UC 49: A publisher wants to provide “teasers” for a book by providing a series of extracts that are meant to give an overview of the book without the need to read the whole publication. This can be typically used by a reseller allowing for a prospective client to access part of the publication free of charge.
• UC 50: EducationalPublisher publishes a complex textbook. The textbook is created is such a way that it could be used both for beginner and advanced levels. The default reading order corresponds to beginners, but the goal is that advanced students can follow a different path through the material, corresponding to their level of knowledge. EducationalPublisher therefore adds alternative reading orders to the publication that advanced users can follow.
• UC 51: Acme Publishing has published a book on wines that can be read from A-Z, or personalized to only read about red wines or wines from a specific region.
• UC 52: A specialized user agent wishes to find all images in a publication that do not already have alternative text and automatically provide it using an image identification service such as LabelMe.
• UC 53: EducationalPublisher publishes a history textbook in English. The textbook contains two glossaries, one in English and one in Spanish for Spanish-speaking students learning English as their target language to facilitate their ability to understand key terms in the text. A specialized user agent should be able to reveal and suppress the Spanish glossary based on what the student requires.
• UC 54: A foreign language textbook Web Publication allows for a specialized user agent to filter and display content identified as vocabulary and conjugation charts. This is done in order to facilitate the teacher creating study guides.
• UC 55: CookbookPublisher wants to create a cookbook that either a function within the publication itself or a feature in a user agent can filter to only show recipes with certain labels.
• UC 56: The publisher of an experimental novel would like to publish the book as a Web Publication. The author wishes the reader to have the option to read chapters in a variety of different sequences, all of which are offered as alternative reading orders in the Web Publication.

• Default Reading Order
• Table of Contents

Req. 12: If there is a physical book version of the Web Publication, the user must have the ability to quickly browse to a corresponding pointer as identified in the physical book.

• UC 57: Beatrix is visually impaired and uses accessible Web Publications in her class, while her sighted classmates use physical books. When the teacher asks the class to open page 71 and read the second paragraph, Beatrix should be able to navigate to exactly the same position in her version as her sighted classmates.
• UC 58: Zoya borrowed a book from her library but must return it. She has decided to buy a WP version of the same text and would like to continue reading where she left off.

• Table of Contents
• Page List

3.7 Alternative Modalities

Req. 13: A Web Publication should encompass publications such as audiobooks, graphic books, mixed media, and interactive media.

All concepts and structures related to a Web Publication should enable the creation and/or production of alternative renderings for visual and auditory content.

• UC 59: Sree wants to access audiobooks while commuting, jogging, doing dishes, or otherwise not able to use his eyes or hands.
• UC 60: Daniel wants to complete his assigned class readings during his commute to work. His textbook Web Publication allows him to access an audio version of the each of the readings.
• UC 61: Khoudia, a librarian focusing on the children's section of her local library, is looking exclusively for material rich in audio and video components so as to reach a wider age bracket.
• UC 62: James, a musician, requires that the musical score within a publication come preformatted in braille music notation in order to read it, as he uses freely available assistive technology which does not have braille music translations built in.

• Publication Types
• Web Publication Bounds
• Links

3.8 Synchronized Time-based Media

Req. 14: A Web Publication needs to support synchronization between text and time-based media.

A Web Publication needs to support time-based media, such as synchronized video, audio, captions or transcript, or sign language interpretation. A Web Publication must also be able to enable a synchronized media experience while navigating through the publication, with sufficient level of granularity.

• UC 63: Illyés has a cognitive disability and uses accommodated texts in the classroom to help learn the content while improving his reading. His assistive technology uses combined audio and highlighted text, which it obtains from the UA through the information provided in the Web Publication, to turn the page for him while reading along in sync with the page currently open.
• UC 64: Marco is learning German as a second language. In order to improve his understanding and pronunciation while reading a German text, he uses a read-aloud function available through his user agent and made accessible by the information provided in the Web Publication.

• Links
• Resource List

3.9 Data

Req. 15: Web Publications should be able to include data as resources, just as it does with text, images, etc.

• UC 65: Rosa has submitted an article to EsteemedJournal and provided her research data in CSV format. She and EsteemedJournal provide users access to the CSVs when accessing her article in any situation by including the CSV data, as well as the Javascript library to display the content in human friendly form, as part of the Web Publication.
• UC 66: A news organization wishes to run a series of articles containing graphs based on a set of raw data. Those graphs are generated dynamically in each article depending on what the topic is. The data is also available to the user for transparency.
• UC 67: An exercise in an educational Web Publication requires the student to push data to a CSV and analyze the subsequent graphs that are dynamically created with each datapoint that the student enters.

• Resource List

3.10 Protection

Req. 16: A Web Publication should allow for application of access control and write protections of the publication.

• UC 68: A library may loan the publication for two weeks or a university may make a textbook available for its students for the course of the year. A Web Publication should provide a means to inform user agents about the availability period to enable the UA to control access accordingly.
• UC 69: Alice is working on potentially Nobel prize winning research and has drafted her paper describing her discoveries. She asks her print disabled friend Bob to review the paper, but needs to make sure that the Web Publication retains specific protections on what Bob is able to do with the publication without restricting Bob's assistive technology from accessing the content.

• Privacy Policy

3.11 Packaging

Req. 17: It should be possible to create and distribute a Web Publication as a single unit over different protocols or physical media.

This can be done through the usage of Packaged Web Publications.

• UC 70: HA, Ltd, a publisher of legal briefs, needs to distribute content in a consumable format to its clients via secure email.
• UC 71: Dalia, a patent lawyer, wants to consume content on a multitude of devices, some of which may not always have connectivity. In order to meet her expectations, it is necessary to have all required content grouped in a logical structure that can be easily transferred between devices.
• UC 72: Andreas is working on his first collaborative research paper with a fellow student. He wants to share a relevant publication that includes content, diagrams, and datasets with his writing partner. He does not have time to learn how to share each component so that his partner can access it all without much effort; he expects to be able to share this material as a single unit via the chatting system that they use to collaborate.
• UC 73: Dave is reading Moby Dick on his tablet (at home with network connectivity). He then jumps on a plane with his good friend Tzviya. After having finished reading the book, he wants to lend it to Tzviya, so that she can start reading on her own tablet. They are both offline, but can exchange data with SD cards or Bluetooth.
• UC 74: Giselle is an independent author who has produced the audio version of her latest novel. She wants to distribute it directly to a few beta readers before launch without worrying about sending a list of files with no structure.

• Links
• Web Publications

Req. 18: A Packaged Web Publication (PWP) should include means to map the identification of a constituent resource between the Web and its equivalent in a package.

In order to allow a Web Publication to be packaged without any changes to the content, it may be necessary to provide a mapping from the (absolute) URLs present in the publication to URLs that point to the constituent resources inside the package.

• UC 75: An archival service wants to harvest (spider) a Web Publication and not have to modify the OWP content during the process. In order to achieve that goal, its manifest would incorporate a mapping from the URIs present in the OWP content to their new location inside the archive.

• Web Publication Bounds
• Default Reading Order

Req. 19: The publisher should be able to provide information in a Packaged Web Publication that can be used to check the origin of the publication and its authenticity.

• UC 76: Michael, who is a lawyer, and uses the publications of LegalPublisher Ltd., must be 100% sure that the publication he uses for his case has indeed been published by LegalPublisher Ltd. and not by a possible third party. This can be done because LegalPublisher Ltd. adds the necessary cryptographic information to the Web Publication proving its own identity.
• UC 77: Brendan wants to make sure that the version of a textbook Web Publication that he wants to purchase from an online retailer is the correct one required for his class.

• Creators
• Linked records

Req. 20: The publisher should be able to provide information in a Packaged Web Publication proving that the publication has not been tampered with during delivery.

• UC 78: Luke has written another book, this time using all of the capabilities of the Open Web Platform that he can think of, including using the readers location to adapt the content. He submits the book for review to a Web Publication retail platform where the book is signed by the publisher. When purchased, the user agent detects that the book came from a trusted source and has not been modified, therefore allowing it to use the full capabilities of the web platform.
• UC 79: LegalPublisher Ltd. regularly publishes the official legal texts and regulation as decided by the local government. Michael, who is a lawyer, has access to these documents via his law firm and uses them for his cases; to do so, he must be 100% sure that the publication he accesses faithfully reproduces the latest governmental decisions. This can be done because LegalPublisher Ltd. adds the necessary cryptographic information to the Web Publication that becomes invalid if any resource of the Web Publication changes.

• Creators

4.1 Time-based Media

Req. 21: If a Web Publication contains time-based media, a user agent should provide a player interface that is accessible.

The player interface should allow for the following use cases:

• Experiencing an audiobook, video, or other time-based media to completion without user interaction
• Experiencing an audiobook, video, or other time-based media at the user's desired pace without audio distortion

• UC 80: Helga wants to cook, drive, or run while listening to an audiobook and can’t be interrupted by any request for additional inputs.
• UC 81: Yitian is listening to an audiobook on a device where the only input available is play and pause.
• UC 82: Suraj wants to listen to an audiobook on his smart speaker by using a voice input to start the playback.

• Audiobook

Req. 22: In time-based media in a Web Publication, It should be possible to navigate not only by chapter/section but by short segments of time.

• UC 83: Mateus is writing a book review and wants to find a specific segment in the audiobook to quote and review. He remembers it’s early in chapter 3, so he wants to open the audiobook to chapter 3 and listen, skipping forward in ten second increments using the player provided by the user agent, until he finds it.
• UC 84: Delta is listening to an audiobook in her car but realizes she missed the last 30 seconds because she was merging onto a highway and wasn’t focused on the content. She wants to pan back 30 seconds to listen to the content she missed.
• UC 85: Stanford just opened his audiobook and wants to skip through the copyright and title info as well as the dedication without opening up the table of contents.
• UC 86: Sasha is rewatching a video in her educational Web Publication for a refresher and wants to skip over introductory content and content that she already has a firm understanding of.

• Audiobook

Req. 23: If a Web Publication contains time-based media, a user should be able to understand the duration of the media, both in its entirety and of its constituent parts.

• UC 87: Bruce is watching a series of videos in a Web Publication and wants to know how long it will be until the next video plays. He is able to view the duration of the current video in the player interface of the user agent.

• Audiobook
• Duration

4.2 Progression

Req. 24: User agents should provide the option for the user to save their progression in the publication and return the user to the last location they saved the next time they open the publication.

• UC 88: Ann is visually impaired and is reading a sample test paper with objective-type questions. The answers of the test are given at the end of the publication. Ann needs to read the question one at a time and then check if her answer is correct. Therefore she must bookmark both the questions and answers provided at the end of the book so that she is able to switch between the both efficiently.
• UC 89: Mateusz runs a Dungeons and Dragons campaign. He would like to be able to mark off specific sections of different rulebooks and share those bookmarks so that players in his game can quickly reference the material.
• UC 90: Aika is reading a novel on her 9-inch tablet, bookmarks her location, and switches to her 5-inch phone. She would like to be able to resume reading from the same point where she left off, given that she may not be using the same user agent on each device that contains some mechanism that would sync the content position.
• UC 91: Julia prepares her lessons for the next day. In her textbook Web Publication, she bookmarks several locations while doing her prep.

4.3 Reading State

Req. 25: The user must be able to leave the Web Publication and return to it at the last position they left from. The User Agent must retain the reading position, based on the last known position of the reader in the Web Publication. The position should be based on the reader's position in the file within the reading order.

The user agent may retain reading state if the web publication is revised. If the user agent consists of a player interface, that interface should allow the ability to leave and return to the content in the same position where the reader left off.

• UC 92: Filbert is reading a comic as a Web Publication. He exits the user agent without bookmarking or saving his location in the Web Publication. When he returns the next day, he opens the Web Publication and continues reading from where he had left off.
• UC 93: Sainath fell asleep the last time he was listening to his audiobook. When he opened it for his next listening session it was on chapter 6 but he needs to navigate back to chapter 3 because that’s the last one he remembers listening to.
• UC 94: Nelleke is listening to The Iliad on her walk to work. The audiobook is 14 hours long, but her walk only takes 30 minutes. She would like to stop the playback when she arrives and continue where she left off on her trip home.

• Page List
• Resource Categorization Properties
• Default Reading Order

4.4 Movement

Req. 26: It should be possible to see the Web Publication in a “paginated” view. When a user agent renders a Web Publication in a paginated layout, it must lay out each document in the default reading order sequentially, with the last page of a resource being followed by the first page of the subsequent one.

Whereas a “scrolling” view is the dominating approach on the Web in browsers, a user or author may wish to view their publications in a paginated view. As such, it should be possible for an individual publication or user agent to provide the ability to switch to pagination view. This pagination may automatically adapt page sizes to the device’s or the browser’s viewport and may contain separate headers, footers, and/or page numbers.

This is distinct from the need to retain original page numbering (often from the print edition) which must be available on demand and must be usable to discover specific locations in the publication.

For more detailed requirements on pagination, see here.

• UC 95: Ann reads War and Peace which, when printed, is over 1200 pages. In order to have a better sense of her progress in the book and to make navigation within the book easier (i.e., to support usability), she decides to switch her reading environment to paged view.
• UC 96: Susan uses a flexible CSS layout that includes images to create a rich, interactive publication on the history of a city. Each major historical milestone is defined as a standalone unit that would be a single page when printed, with a timeline with the main events in the footer area of the page.
• UC 97: IndyPublisher wants to provide transition effects between pages, both within and across content documents.
• UC 98: Mr. Oayia, a classroom teacher, says, “Turn to page 137 of your textbook.” Regardless of layout and font size, students reading digital editions need to find the same location in the textbook as one another and as students reading the print edition.
• UC 99: Alphonse has been listening to an audiobook he enjoys and would like to share a section with a friend. He tells his friend that the position of the quote is "Chapter 5, 2:33". His friend is able to find the section with the audiobook player module provided by his user agent.

• Page List
• Resource Categorization Properties
• Default Reading Order

4.5 Offline

Req. 27: A Web Publication should also be available offline.

The same content of the Web Publication should be accessible offline, if circumstances so dictate, without the necessity for the user to take any particular, technical actions.

• UC 100: Omo, a student in a remote Nigerian village, is taking classes online. Connectivity in the village is unreliable and intermittent. Omo needs to have his textbooks available regardless of actual connectivity.
• UC 101: Heather, a frequent international traveler, enjoys reading books and tour guides on her portable device, regardless of her physical location on any given day. Due to the high mobile network access roaming charges on her mobile network, she tends to download as much of her reading material as possible where she can avoid those additional charges.
• UC 102: Gemma is building a private collection of publications that she expects to be available to her whether online or offline, over the public Internet, or within a private local area network (LAN).
• UC 103: In-house documents may have to be accessed both online and offline, depending on the access point. While online access might be beneficial when done from the work floor (e.g., at an airplane production line), the same documents may need reliable offline access (e.g., in the cockpit).
• UC 104: Gyöngyi, selected as a peer reviewer for the Journal of Scholarly Publications, only has time to review her assigned publication while commuting on the train to her university where she does not have connectivity. Since her review process includes the creation of annotations, notes, highlights, and possibly changes on the content itself, it is important that these changes be smoothly transferred back to the server of the journal when she is back online.

• Scope
• Resource List

Req. 28: A user agent needs to know the information required to allow the user to access content offline or actively streaming, based on the size and nature of the content, and conditions imposed by the user.

• UC 105: João lives in Recife where he has very spotty internet and slow download speeds. He enjoys listening to audiobooks during his morning bike ride and would like to listen to his books before they complete downloading, as fully downloading a book could take several days.
• UC 106: Rich is watching a video embedded in his textbook WP for a class. He is streaming the video rather than waiting for it download because he does not have enough space on his device to download all the videos required to watch for the class.
• UC 107: Wendy is running late for work but wants to listen to her audiobook on her commute. As she leaves she realizes she has not yet downloaded it, but there is no Wi-Fi available. She has plenty of data and decides to stream the content as she makes her way to the office.
• UC 108: Sally is preparing for a flight from London to LA tomorrow. She would like to listen to an entire Web Publication during the flight, which does not have Wi-Fi. Via her user agent, she is able to listen to the Web Publication offline.

• Scope
• Resource List
• Audiobook

4.6 Personalization

Req. 29: The user must have the possibility of personalizing his or her reading experience. This may include, for example, controlling such features as font size, choice of fonts, background and foreground color, tone of audio, etc.

• UC 109: Olga, a dyslexic student, downloads a textbook and proceeds to personalize the material with larger and/or a specialized dyslexic font, as well as different contrast that, for her particular case, makes the text easier to consume.
• UC 110: When reading a book in the sun, Mia adjusts the background color to allow for a stronger contrast so that she can see the text.
• UC 111: While reading a book on computer programming, Ransheed wants to change the font into a local font. However, the code samples within the text should remain in a fixed-width font.
• UC 112: Buffy is deafblind. Every morning she downloads her daily newspaper. Like most news sites, it provides many rich multimedia presentations. As a high-quality, accessible news site, its multimedia presentations come with captions and transcripts. Buffy does not want to waste her data plan on the useless-to-her audio and video content, so she instructs her user agents to ignore them.

• Language and Base Direction
• Accessibility

4.7 Non-WP User Agents

Req. 30: A non-WP user agent should be able to access the content of a Web Publication.

Since Web Publications are based on the Open Web Platform, a Web Publication's constituent HTML pages, video, audio, images, interactive components, and other media, should be accessible to a non-WP user agent. Creators of Web Publications should allow for the user to be able to access this content.

Special consideration should be given to Web Publications where time-based media is the main or only component, such as an audiobook. To allow the user to access this content, the Web Publication should provide the user with the ability to:

• Display title and duration of the book to the user
• Play chapters defined in the book one after the other. It may not include end to end continuous reading of the book
• Navigate to a chapter defined in the book and start playback from there
• Pause and resume
• Start playing from a page number or a time point defined in the book
• Forward and rewind by some time interval

• UC 113: John found an audiobook Web Publication in his university, which he wants to start listening to immediately, but he does not have an audiobook user agent installed on his university computer. He at least should be able to use the basic functionality of the book in the vanilla browser available on the university computer.

• Resources
• Address
• Audiobook

4.8 Packaging

Req. 31: The distribution of a Packaged Web Publication should not affect its iterations.

Simply distributing or sharing a Packaged Web Publication to multiple destinations and devices should not result in (technically) different iterations of the Web Publication unless they contain modifications that make them different Web Publications.

• UC 114: Publisher Corp. Inc. publishes a new Packaged Web Publication and sends it to its distributors and customers. This Packaged Web Publication is downloaded to devices or made available to a customer-specific cloud. Customers can access this file from different retailers, through different applications, either directly or downloaded from a private cloud. Thus, the Web Publication is duplicated many times, resulting in a huge number of copies. There remains a single source manifestation, and therefore one canonical identifier, for all of the items spread across devices and buyers.
• UC 115: EducationalPublisher wants to create a custom version of their textbook WP for an instructor. Content from a few additional sources is added, but the original WPs are not affected.
• UC 116: Mary creates a Packaged Web Publication and sends it to Dave and Kristin. Kristin simply sends it along to two other friends, but Dave adds some comments first to his copy before sending to two friends. By doing so, Dave has created a new Web Publication with its own canonical identifier, while the version used by Mary, Kristin, and her friends remains the same as the original.
• UC 117: Slicendice Publishing publishes many Packaged Web Publications, some of which are different iterations or subsets or combinations of others. Slicendice needs not only to be able to uniquely identify each Web Publication but also to identify each “copy” or “delivery” (“item”) of each of those Web Publications so that it can track what has been sold and how many of each one have been sold.
• UC 118: BigRetailer receives a Web Publication from EsteemedPublisher that it intends to add to its catalogue. BigRetailer wants to add its own “teaser” via an alternative reading order. To achieve that, BigRetailer provides its own version of the publication’s manifest that the user agent will use instead of the publisher’s manifest.

• Linked records

Req. 32: The distribution of Packaged Web Publications should respect the existing processes and expectations of professional publishing channels as well as ad-hoc methods of distribution (e.g., email).

• UC 119: Ahmed acquires a Packaged Web Publication on an e-commerce platform. He expects to be able to receive the Web Publication as a file (rather than only having access to it online) and to be able to load it onto his different reading devices.
• UC 120: Alice acquires a Packaged Web Publication through a subscription service and downloads it. When, later on, she decides to unsubscribe from the service, this Web Publication becomes unavailable to her.
• UC 121: Leila has just written a report for school as a Web Publication, but she is required to email it to her teacher. She takes advantage of the fact that it is possible to package up a publication and then sends it off.

4.9 Archiving

We take for granted the relative durability of print artifacts, many of which have survived with little more than benign neglect. In contrast, digital documents are unlikely to persist without more active interventions, such as making copies, monitoring software dependencies, and validating integrity. Since future consumers of publications represent the most open-ended user group, it is desirable that digital documents be instilled with more of the inherent durability that characterizes print artifacts. Packaged Web Publications offer this potential by making it easier for archiving services to locate, harvest, update, and describe digital publications. Long-term preservation of digital publications ensures that they may continue to be accessible beyond the tenure of individual authors, file formats, publishers, or publishing platforms.

Fundamental use cases and requirements already help aid our archiving requirements (e.g., Req. 7: The information regarding the constituent resources of a Web Publication must be easily discovered and there should be a way to differentiate between essential and non-essential resources. ). However, archiving raises additional requirements:

Req. 33: There should be a way to indicate whether one or more Packaged Web Publication components contain (embedded) descriptive metadata.

An archiving service needs a reliable way to determine which, if any, Web Publication components contain descriptive metadata, such as those described in metadata and resources. Without such a mechanism, the archiving service will have to develop and maintain publisher- and/or platform-specific heuristics for locating or parsing out descriptive metadata, making archiving more expensive and decreasing the reliability of reporting.

• UC 122: An archiving service sets out to conduct an initial harvest of an article. Along with the images, markup, scripts, and style and layout instructions that constitute the object, it is able to locate a file containing descriptive metadata. The archiving service retrieves these resources and packages them into a logical archival unit for ingestion into a preservation repository. A related process identifies and parses the descriptive metadata and saves its contents into an associated management database.

• Linked records
• Title

Req. 34: There should be a way to discover that one or more new components have been added to or deleted from a Web Publication.

An archiving service needs a reliable way to learn that one or more Packaged Web Publication components have been added to or removed from a Packaged Web Publication in order to be able to update the associated archive of the publication.

• UC 123: An archiving service regularly polls for changes to an article that it has already archived. One such poll indicates that several resources have been added to the object. The archiving service retrieves these resources and stores them as incremental updates to the appropriate archival unit in a preservation repository.
• UC 124: A publisher issues a retraction for a published article, resulting in the addition of new resources to the object (i.e., the retraction notice) and the removal of others (i.e., the article content). An archiving service regularly polls for changes to this article, which it has already archived, and discovers the retraction. The archiving service retrieves the new resources and records those that are no longer accessible, carrying over the cumulative updates to a preservation repository.
• UC 125: A copyright dispute results in the takedown of a published book. An archiving service regularly polls for changes to this book, which it has already archived, and discovers that it has been taken down. It records that the resources that constitute the object are no longer accessible and propagates this update to a preservation repository.
• UC 126: A student writing a research report wishes to refer to changes in a certain Web Publication. The student would like to compare changes across different iterations of that Web Publication and cite an archival service.