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EPUBCheck · Package and ZIP container

EPUBCheck PKG-012: non-ASCII letters in file name

Updated:

EPUBCheck PKG-012 is a usage message: “The file name "…" contains non-ASCII characters, which might create interoperability issues with older reading systems.” A file name inside the EPUB contains non-ASCII characters (accents, other scripts). That is valid in EPUB 3, but it may break older reading systems, so EPUBCheck reports it as usage information.

The official message

The file name "%1$s" contains non-ASCII characters, which might create interoperability issues with older reading systems.

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

  • Files named after titles in languages other than English, such as "capítulo-1.xhtml".
  • Images exported with the caption or the photographer's name as the file name.

How to fix it

  1. Decide whether you target older devices; if not, you can leave the names as they are.
  2. If you do, rename the file with ASCII characters only.
  3. After renaming, update every reference to the file: the manifest in the package document, links and image sources in the XHTML, and url() references in the CSS.

When it's not this

If EPUBCheck cannot extract the archive at all because of the names, that is PKG-027.

Terms used here

Other PKG messages

  • PKG-011 The file name "…" is not allowed to end with ".".
  • PKG-010 The file name "…" contains spaces, which may create interoperability issues with older reading systems.
  • PKG-014 The EPUB contains empty directory "…".
  • PKG-009 The file name "…" contains characters that are not allowed in OCF file names: ….
  • PKG-008 Unable to read file "…".
  • PKG-016 Use only lowercase characters for the EPUB file extension for maximum compatibility.

Sources

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

FAQ

What does EPUBCheck PKG-012 mean?

EPUBCheck PKG-012 is a usage message: “The file name "…" contains non-ASCII characters, which might create interoperability issues with older reading systems.” A file name inside the EPUB contains non-ASCII characters (accents, other scripts). That is valid in EPUB 3, but it may break older reading systems, so EPUBCheck reports it as usage information.

Is PKG-012 an error?

PKG-012 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.