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EPUBCheck · Resources and references

RSC-029

Updated:

EPUBCheck RSC-029 is an error message: “Data URL is not allowed in this context.” A data: URL (content embedded in the URL itself) is used where EPUB does not allow it.

The official message

Data URL is not allowed in this context.

Default severity
Error. The EPUB breaks a rule of the specification and is invalid. Stores and Send to Kindle may reject it, and EPUBCheck exits with status 1.
EPUBCheck version
5.4.0

Typical causes

  • A data: URL used as a link target or as a document reading apps would navigate to.

How to fix it

  • Save the embedded content as a file in the EPUB, add it to the manifest and reference it by path.

Terms used here

Other RSC messages

  • RSC-028 XML documents must be encoded in UTF-8, but … was detected.
  • RSC-030 File URLs are not allowed in EPUB, but found "…".
  • RSC-027 XML document is encoded in UTF-16. It should be encoded in UTF-8 instead.
  • RSC-031 Remote resource references should use HTTPS, but found "…".
  • RSC-026 URL "…" leaks outside the container (it is not a valid-relative-ocf-URL-with-fragment string)
  • RSC-032 Fallback must be provided for foreign resources, but found none for resource "…" of type "…".

Message text and severity from EPUBCheck 5.4.0 (W3C, BSD-3-Clause). Explanation by EPUBLab.

FAQ

What does EPUBCheck RSC-029 mean?

EPUBCheck RSC-029 is an error message: “Data URL is not allowed in this context.” A data: URL (content embedded in the URL itself) is used where EPUB does not allow it.

Is RSC-029 an error?

RSC-029 is reported as error by default. The EPUB breaks a rule of the specification and is invalid. Stores and Send to Kindle may reject it, and EPUBCheck exits with status 1.