IDPF Adoption Readiness Roadmap
EPUB Dictionaries and Glossaries 1.0

Version 2015-05-18

Supporting tools/documents

1. Samples

2. Epubcheck support

3. Support in EPUB Conformance Test Suite (epubtest.org)

4. Authoring tool support

5. Reading system support

a. Readium (JS & SDK)

b. other open source

c. commercial reading systems

6. Primer/best practice documentation

Deployment impact

7. Backwards compatibility assessment

a. Legacy EPUB 2 RS

b. EPUB 3.0 RS

c. EPUB 3.0.1 RS

8. Fallback feasibility assessment

9a. Polyfilability assessment

9b. Browser compatibility assessment

10. Accessibility implications assessment

Supporting tools/documents

1. Samples

The specification contains samples of individual files (Package Document, Content Document, Search Key Map, etc), in Appendix B.

Additionally, work is in progress to develop a sample of a full-fledged EPUB Dictionary publication based on content extracted from Wiktionary. This sample will likely be made available under the epub-samples project and licensed under the Creative Commons Attribution-ShareAlike 3.0 Unported License.

Another sample of a simple "translation" Dictionary (from English to German) is being finalized by Wolfgang Schindler of PONS GmbH.

Merriam-Webster is producing several titles conforming to the EPUB Dictionaries specification and is open to providing samples to developers under NDA.  They expect at least two titles to be ready by end of Q2 2015.

2. Epubcheck support

Initial support for EPUB Dictionaries and Glossaries schema-based validation will be integrated in the next major release of EpubCheck, version 4.0, which is expected by the end of Q2 2015.

3. Support in EPUB Conformance Test Suite (epubtest.org)

EPUB Dictionaries and Glossaries working group co-chairs organized a joint conference call in September 2014 with people from the EPUB Test Suite project (Julie Morris, Bill Kasdorf, and Marisa DeMeglio) and one co-chair of the EPUB Indexes working group (Dave Ream).

The Working Group will take on the responsibility of creating initial test cases, in close collaboration with Marisa DeMeglio.

4. Authoring tool support

Dictionary publishers generally store their data in their own flavor of XML and write their own tools to convert it to other formats as needed.  We do not anticipate having any general purpose conversion or authoring tools available for initial spec release.  However, we do anticipate that some publishers (eg, PONS) or service providers (eg, Intangible Press) will have tools to convert specific publisher XML to EPUB DICT at or just after spec publication.

5. Reading system support

  a. Readium (JS & SDK)

Our understanding is that the necessary resources are not immediately available to implement the specification. The likely timeframe for implementation needs to be discussed with Readium team.

  b. other open source

The Working Group is not aware of any planned open source implementation.

  c. commercial reading systems

Helicon Books plans to implement the EPUB Dictionaries and Glossaries specification once a sample dictionary is available.

Yasuo Kida of Apple was a key participant in the development of the specification. Our earlier understanding was that Apple was likely to implement it; however, we do not have any information on their current plans.

6. Primer/best practice documentation

Specification examples and informative passages are intended to serve as best practice guidelines.

Deployment impact

7. Backwards compatibility assessment

What will be the impact of content deployment on the following categories of RS (assuming that they have not yet been updated to explicitly support the given specification)?

  a. Legacy EPUB 2 RS

Same as standard EPUB 3.0.1.

  b. EPUB 3.0 RS

Same as standard EPUB 3.0.1.

  c. EPUB 3.0.1 RS

A Publication conforming to the EPUB Dictionaries and Glossaries specification is perfectly readable in compliant EPUB 3.0.1 Reading Systems. The specification mostly adds a number of new properties for use in the epub:type attribute.

The specification does define a new Core Media Type (for Search Key Map Documents). This new media type is not a Content Document and does not interfere with the rendering of a Publication. However, a Reading System that does not yet support EPUB Dictionaries and Glossaries needs to ignore the new type and not reject the Publication altogether.

8. Fallback feasibility assessment

Describe any explicit fallback behaviors incorporated in the given specification.

Because the Specification is entirely backwards-compatible, no explicit fallback mechanisms are necessary for this spec (see item 7 above) and none are provided.

The new Core Media Type defined for Search Key Map Documents is not required for rendering and can simply be ignored.

9a. Polyfilability assessment

Can support for the given feature(s) be added via a JS polyfill (embedded in content)?

Rendering an EPUB Dictionary or EPUB Glossary as standard EPUB is totally backward-compatible, as mentioned in item 7 above.

However, the specification indicates in its section 3.2 that a conforming Reading System must provide a means to perform a lookup of a user-provided word or phrase. This could be implemented with a polyfill to allow the user to type in a word and look it up within the EPUB Dictionary Publication itself (or Publication containing a glossary).  However, a polyfill would not cover the case when the user is reading another Publication and wants to lookup a word in an external  EPUB Dictionary.

9b. Browser compatibility assessment

Does implementation of the given feature(s) require changes to the underlying browser engines of RS?

The EPUB Dictionaries and Glossaries specification does not require any change to the underlying browser engine of an EPUB 3.0.1 Reading System.

10. Accessibility implications assessment

Are there any noteworthy (positive or negative) implications on accessibility in the given feature(s)?

The EPUB Dictionaries and Glossaries specification generally increases the semantic richness of the Content Document markup, so it is likely to generally enhance accessibility. Dictionaries in particular contain many diverse types of information (etymologies, parts of speech, examples, etc.), and our specification allows Reading Systems or Authors  to use dictionary semantics to improve accessibility (e.g. in audio cues or custom CSS).

Note that the User Interface required to implement conforming lookup functionality is the responsibility of the Reading System and is not defined by this specification. As such, its accessibility depends on the Reading System.

Note also that the Search Key Map Document definition does not allow Authors to define custom pronunciation information or lexicons; rendering of search keys depends on the lookup User Interface and is expected to rely on the underlying platform's TTS capability.