Providing the file size, format, and EPUB version ensures an accessible reading experience and compatibility with various reading systems.

Objectives

• Improve user experience by providing essential download and readability information.
• Anticipate compatibility between the EPUB file and the reading system.
• Increase the transparency and interoperability of EPUB content.

Implementation

• Provide the following technical specifications: file size, format (reflowable or fixed-layout), and EPUB version (e.g., 3.2) via ONIX metadata (use ProductFormDetail for format, ProductFormFeature for EPUB version, and FileSize for file size).

Control

• Check that the values for ProductFormDetail, ProductFormFeature, and FileSize are accurate and match the actual file.