# RSC-006b: remote resource for a script, how to fix it

Source: https://epubcc.com/epubcheck/rsc-006b/ (updated 2026-11-04)

EPUBCheck RSC-006b is a usage message: “Resource "…" is located outside the EPUB Container; please check the resource is retrieved in scripted content.” A resource is located outside the EPUB container, and EPUBCheck asks you to check that a script fetches it. It is a usage message, shown only with -u; resources retrieved through scripting APIs may legitimately be remote.

- Official message (EPUBCheck 5.4.0): Resource "%1$s" is located outside the EPUB Container; please check the resource is retrieved in scripted content.
- Default severity: Usage

## Typical causes

- A scripted document that loads data or media from a server.
- A remote reference in a place EPUBCheck cannot classify, such as markup a script uses.

## How to fix it

1. Confirm the resource really is fetched by a script; if so, nothing needs to change.
2. If it is an image or stylesheet the page displays directly, move it into the EPUB, add it to the manifest and use a relative path.
3. Remember that reading apps may run without network access, so the book should still work without it.

## When it's not this

If the remote resource is used where EPUB forbids it, EPUBCheck reports the error RSC-006 instead.

## Sources

- EPUB 3.3, §3.6 Resource locations: https://www.w3.org/TR/epub-33/#sec-resource-locations (read 2026-11-04)
- EPUB 3.3, §6.3.2 Scripting: https://www.w3.org/TR/epub-33/#sec-scripted-content (read 2026-11-04)

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