# EPUBCheck OPF-085: dc:identifier value … is marked as a…

Source: https://epublab.com/epubcheck/opf-085/ (updated 2026-11-03)

EPUBCheck OPF-085 is a warning message: “"dc:identifier" value "…" is marked as a UUID, but is an invalid UUID.” A dc:identifier says it is a UUID (urn:uuid:) but the value is not a valid UUID.

- Official message (EPUBCheck 5.4.0): "dc:identifier" value "%1$s" is marked as a UUID, but is an invalid UUID.
- Default severity: Warning

## Typical causes

- A shortened, mistyped or invented value after urn:uuid:.

## How to fix it

- Use a real UUID in the form 8-4-4-4-12 hexadecimal digits, or drop the urn:uuid: prefix if the identifier is something else.

Message text and severity: EPUBCheck (W3C, BSD-3-Clause). Explanation: EPUBLab.