# EPUBCheck RSC-008: Referenced resource … is not declared…

Source: https://epublab.com/epubcheck/rsc-008/ (updated 2026-11-03)

EPUBCheck RSC-008 is an error message: “Referenced resource "…" is not declared in the OPF manifest.” A file exists in the EPUB and is referenced, but the package document's manifest does not list it.

- Official message (EPUBCheck 5.4.0): Referenced resource "%1$s" is not declared in the OPF manifest.
- Default severity: Error

## Typical causes

- An image or stylesheet added to the book folder without updating the manifest.

## How to fix it

- Add an item for the file to the manifest with a unique id, its path and its media type, for example <item id="fig1" href="images/fig1.png" media-type="image/png"/>.

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