Overview - ISO/IEC 23736-1:2020 (EPUB 3.0.1 Overview)
ISO/IEC 23736-1:2020 is the ISO/IEC adoption of the EPUB 3.0.1 Overview specification. It provides an informative introduction and roadmap to the EPUB 3 family of standards for digital publishing. EPUB 3 is an interchange and delivery format based on XML and Web standards (HTML5, CSS, SVG) designed for creating, packaging and distributing digital publications (.epub). This part is primarily an explanatory document meant to be read alongside the normative parts that define semantics, packaging and media synchronization.
Key topics and technical requirements
- EPUB architecture and components - Describes the structure of an EPUB Publication: resources bundled in a ZIP-based EPUB Container, the /META-INF directory, and the container.xml file that points to Package Documents.
- Package Document (OPF) - Central manifest for each Rendition: lists resources, metadata, and the reading order (spine) for linear consumption.
- EPUB Content Documents - Profile of XHTML, SVG and CSS for EPUB; includes EPUB-specific constructs such as epub:type and epub:trigger.
- Navigation - The EPUB Navigation Document (XHTML nav) replaces NCX and provides machine- and human-readable navigation, including reading order and table of contents.
- Media Overlays and SMIL - Defines synchronization of text and audio (EPUB Media Overlays 3.0.1), using SMIL for timed relationships between audio and Content Documents.
- Open Container Format (OCF) - ZIP-based container format and processing model for packaging EPUB resources (.epub).
- Linking and location addressing - EPUB Canonical Fragment Identifier (epubcfi) enables interoperable linking, bookmarking and shared reading locations across devices.
- Accessibility and global language support - Guidance on semantic markup, text-to-speech, aural renditions, fallbacks, and support for international typography and fonts.
- Fixed layouts and rendering - Metadata and mechanisms for fixed-layout publications (comics, children’s books, magazines) and CSS-driven rendering considerations.
Practical applications and users
Who uses this standard:
- Publishers and content authors creating ebooks, magazines, educational materials, comics and fixed-layout books.
- Reading system and e-reader developers implementing EPUB rendering, navigation, accessibility and media synchronization.
- Accessibility specialists and educational content creators building synchronized audio (media overlays) and TTS-capable content.
- Tool and workflow vendors (conversion, packaging, validation) producing .epub outputs that conform to EPUB 3.0.1.
Practical uses:
- Producing distributable .epub files that support rich media, global typography, and accessibility.
- Implementing synchronized audio narration for audiobooks and read-aloud features.
- Creating fixed-layout publications with precise page control and orientation.
- Enabling cross-device bookmarking and linking via epubcfi.
Related standards
- EPUB Publications 3.0.1 (Publications301) - semantics and conformance
- EPUB Content Documents 3.0.1 (ContentDocs301) - XHTML/SVG/CSS profiles
- EPUB Open Container Format 3.0.1 (OCF301) - packaging and container
- EPUB Media Overlays 3.0.1 (MediaOverlays301) - text/audio synchronization
- EPUB Canonical Fragment Identifier (EPUBCFI) - locating positions in EPUB content
Keywords: EPUB 3.0.1, ISO/IEC 23736-1, digital publishing, EPUB Media Overlays, SMIL, Package Document, OCF, Content Documents, accessibility, fixed layout, epubcfi.