# OPF-018b: remote-resources unverified, how to fix it

Source: https://epubcc.com/epubcheck/opf-018b/ (updated 2026-11-04)

EPUBCheck OPF-018b is a usage message: “The "remote-resources" property was declared in the Package Document, but no reference to remote resources has been found; please check scripted content to make sure the property is legit.” A manifest item declares remote-resources, no remote reference was found, and the document is scripted. Because a script can load files from the web at run time, EPUBCheck cannot tell, so it only reports a usage note (shown with -u).

- Official message (EPUBCheck 5.4.0): The "remote-resources" property was declared in the Package Document, but no reference to remote resources has been found; please check scripted content to make sure the property is legit.
- Default severity: Usage

## Typical causes

- A scripted document that once loaded remote content and no longer does.
- A template that declares both scripted and remote-resources on every document.
- A script that does fetch remote files, which EPUBCheck cannot see; in that case the property is right.

## How to fix it

1. Open the document and check what its scripts load.
2. If a script fetches anything from an http or https address, keep remote-resources.
3. If nothing remote is loaded, remove remote-resources from the manifest item.

## When it's not this

If the document has no scripts, the same situation is reported as OPF-018, a warning.

## Sources

- EPUB 3.3, §D.6.4 remote-resources: https://www.w3.org/TR/epub-33/#sec-remote-resources (read 2026-11-04)

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