Sustainability of Digital Formats: Planning for Library of Congress Collections

EPUB Version 3.0.1, published in June 2014, was a minor maintenance update to EPUB 3.0, published in October 2011. For more information about the structure of an EPUB file, and for analysis in relation to sustainability and functionality, see EPUB_3_0. This description focuses on changes introduced in the update to EPUB 3.0.1. See EPUB 3.0.1 Changes from EPUB 3.0.

• The nature of the contents of an OCF Container was clarified to explicitly disallow bundling of renditions of different publications in the same container.
• Support for fixed-layout publications, formerly specified in EPUB 3 Fixed-Layout Documents (2012), was merged into the EPUB 3.0.1 specifications. Fixed-layout metadata properties were now defined in EPUB Publications 3.0.1: 4.4.2 Fixed-Layout Properties. Support in EPUB 3 Reading Systems for fixed layout was made mandatory.
• All EPUB Content Documents linked to from EPUB Content Documents listed in the spine element were now required to be listed in the spine. All EPUB Content Documents linked to from the EPUB Navigation Document were also now required to be listed in the spine, regardless of whether the Navigation Document is included in the spine.
• A new collection element provided a framework for developing specialized behaviors and rendering in EPUB 3. It provided an extension point on which functionality could be built. It was being used, for example, to allow an index split across multiple XHTML Content Documents to be identified and rejoined (e.g., for machine processing and presentation). See What is a Collection.
• The use of semantic markup based on RDFa Core 1.1 - Second Edition or HTML Microdata (W3C Working Draft 25 October 2012) was now allowed in XHTML Content Documents. Vocabularies, such as those defined at schema.org, could now be used to support machine processing to enrich content. See Web Data Commons -- Microdata, RDFa, JSON-LD, and Microformat Dataset Series.
• Several lists of permitted values were moved to external documents to allow updating without requiring a new edition of the standard. The list of reserved prefixes that can be used in Content Documents, was moved to EPUB Content Document Reserved Prefixes. The vocabulary of properties that could be used in the rel attribute of the link element was moved to the EPUB Link Relationships Vocabulary. The list of reserved prefixes that can be used in package metadata, such as for MARC and ONIX bibliographic data, was moved to EPUB Publications Reserved Prefixes.

Open standard, publicly documented. Developed under the auspices of the International Digital Publishing Forum (IDPF).

Adopted as an international standard by ISO/IEC JTC1 as ISO/IEC 23736:2020 in six parts. Within ISO and IEC, EPUB is considered by a special joint working group (ISO/IEC JTC 1/SC 34/JWG 7). JWG 7 spans several ISO and IEC committees: JTC 1/SC 34 (Document description and processing languages), ISO TC 46/SC 4 (Technical interoperability), and IEC/TC 100/TA 10 (Multimedia e-publishing and e-book technologies).

Specifications for EPUB version 3.0.1 from IDPF.

Also available from ITTF Publicly Available Standards.

EPUB 3.0.1 is the most widely adopted version of EPUB. See also EPUB_3_0.

See EPUB_3_0.

• The bytes “PK” will be at the beginning of the file, followed by two additional bytes from the ZIP specification: \003 \004
• The bytes “mimetype” will be at position 30
• actual MIME type (i.e., the ASCII string “application/epub+zip”) will begin at position 38

EPUB 3.0.1, published in June 2014, was a minor maintenance update to EPUB 3.0, which had been published in October 2011. For earlier history of the EPUB format, see EPUB_3_0.

The next version of EPUB to be published was EPUB 3.1. In early 2019, EPUB 3.1 was declared defunct because of lack of adoption due to incompatibility with earlier releases of EPUB 3. See introduction to EPUB 3.1 on IDPF website.

At the end of January 2017, the World Wide Web Consortium (W3C) and the International Digital Publishing Forum (IDPF) combined organizations. See IDPF News as of January 31, 2017 and New Roadmap for Future of Publishing is Underway as W3C and IDPF Officially Combine from Publishing@W3C on February 1, 2017. Development of EPUB continued under the auspices of the W3C EPUB Community Group. EPUB 3.2 was published in May 2019 by W3C as a Final Community Group Specification.