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EPUBCheck · Package document (OPF)

EPUBCheck OPF-090: older media type used

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. It is a usage note (shown with -u): the older type is still accepted.

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

  • Fonts declared as application/vnd.ms-opentype or application/font-woff instead of font/otf or font/woff.
  • Manifests written before the current media types were registered.
  • Tools that still write the older names.

How to fix it

  1. Read the two media types in the message.
  2. Change the manifest item's media-type to the one EPUBCheck suggests.
  3. The file itself does not change; nothing else needs updating.

When it's not this

If the declared type does not match the file at all, that is OPF-029.

Terms used here

Other OPF messages

  • OPF-089 The "alternate" link rel keyword cannot be paired with other keywords.
  • 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.

Sources

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

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. It is a usage note (shown with -u): the older type is still accepted.

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.