# RSC-011: link to a non-spine document, how to fix it

Source: https://epubcc.com/epubcheck/rsc-011/ (updated 2026-11-04)

EPUBCheck RSC-011 is an error message: “Found a reference to a resource that is not a spine item.” A hyperlink points to a content document that is in the manifest but not in the spine, so reading apps may not be able to open it. Every document a reader can navigate to must be part of the spine.

- Official message (EPUBCheck 5.4.0): Found a reference to a resource that is not a spine item.
- Default severity: Error

## Typical causes

- A note, appendix or answer page linked from the text but never added to the spine.
- A document removed from the spine to hide it, while links to it remained.

## How to fix it

1. Find the target document named in the message.
2. Add the document to the spine. If it should not appear when paging through the book, add it with linear="no".
3. Validate again.

## When it's not this

If the target file is missing entirely, that is RSC-007; if it is not a content document, RSC-010.

## Sources

- EPUB 3.3, §5.7 Spine section: https://www.w3.org/TR/epub-33/#sec-pkg-spine (read 2026-11-04)

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