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EPUBCheck · Package document (OPF)

EPUBCheck OPF-018b: remote-resources unverified

Updated:

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).

The official 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.

Default severity
Usage. Informative only and hidden by default: it appears when EPUBCheck runs with -u (--usage). It does not make the EPUB invalid.
EPUBCheck version
5.4.0

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.

Terms used here

Other OPF messages

  • OPF-018 The "remote-resources" property was declared in the Package Document, but no reference to remote resources has been found.
  • OPF-017 The attribute "full-path" on element "rootfile" must not be empty.
  • OPF-016 The element "rootfile" is missing its required attribute "full-path".
  • OPF-015 The property "…" should not be declared in the OPF file.
  • OPF-021 Use of non-registered URI scheme type in href: "…".
  • OPF-014 The property "…" should be declared in the OPF file.

Sources

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

FAQ

What does EPUBCheck OPF-018b mean?

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).

Is OPF-018b an error?

OPF-018b is reported as usage by default. Informative only and hidden by default: it appears when EPUBCheck runs with -u (--usage). It does not make the EPUB invalid.

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