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EPUBCheck · Package document (OPF)

OPF-090

Updated:

EPUBCheck OPF-090 is a usage message: “It is encouraged to use MIME media type "…" instead of "…".” The manifest uses an older media type where a newer one is preferred; EPUBCheck names both.

The official message

It is encouraged to use MIME media type "%1$s" instead of "%2$s".

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

%1$s, %2$s… are filled in with the file, value or element EPUBCheck found.

Typical causes

  • Manifests written before the current media types were registered.

How to fix it

Terms used here

Other OPF messages

  • OPF-091 The item href URL must not have a fragment identifier.
  • OPF-088 Unrecognized epub:type value "…".
  • OPF-092 Language tag "…" is not well-formed: …
  • OPF-093 The "media-type" attribute is required for linked resources located in the EPUB container
  • OPF-086 Property "…" is deprecated. Consider using … instead.
  • OPF-086b epub:type value "…" is deprecated. Consider using … instead.

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

FAQ

What does EPUBCheck OPF-090 mean?

EPUBCheck OPF-090 is a usage message: “It is encouraged to use MIME media type "…" instead of "…".” The manifest uses an older media type where a newer one is preferred; EPUBCheck names both.

Is OPF-090 an error?

OPF-090 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.