To ensure traceability and allow precise identification of which version of an ebook is being accessed, the file version number must be clearly indicated. This information is particularly important for corrections, updates, or errata, as it allows different versions of the same work to be distinguished while retaining the same primary identifier.

Objectives

• Identify which version of the ebook is being accessed.
• Facilitate the management of corrections and successive updates.
• Ensure the traceability of content changes.
• Avoid confusion between different versions of the same work.
• Allow cataloging systems and reading tools to detect updates.

Implementation

• Include the required dcterms:modified metadata in the OPF file to specify the date and time of the last modification.
• State the version number in the legal notices, preferably on the copyright page.
• Update the dcterms:modified date for every content modification, however minor.
• Document changes between versions in a release notes file or within the legal notices.
• Retain the same primary dc:identifier for all versions of the same work, updating only the dcterms:modified date.
• Form a unique package identifier by combining the dc:identifier and dcterms:modified values.

Control

• Check that the dcterms:modified date follows the ISO 8601 format (e.g., 2026-01-14T16:00:00Z).
• Verify that a version mention is present in the legal notices or the copyright page.
• Ensure consistency between the version number in the metadata and the one displayed in the content.
• Verify that the dcterms:modified date is equal to or later than the dc:date publication date.