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EPUBCheck · Package document (OPF)

EPUBCheck OPF-025: list where one value needed

Updated:

EPUBCheck OPF-025 is an error message: “Property value list "…" is not allowed, only one value must be specified.” A metadata property that takes a single value was given a list of values. EPUBCheck names the list it found, and reading apps would not know which of the values to use.

The official message

Property value list "%1$s" is not allowed, only one value must be specified.

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

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

Typical causes

  • Several space-separated values in a property meant to hold one, for example two layout values in one rendition meta element.
  • Two values merged into one element when combining metadata from different sources.
  • A value with a stray space that splits it in two.

How to fix it

  1. Find the meta element or attribute EPUBCheck points to.
  2. Keep a single value.
  3. If parts of the book need different values, set them per item in the spine where the property allows it (for example rendition:layout-pre-paginated on one itemref).

When it's not this

If the single value is malformed rather than doubled, that is OPF-026.

Terms used here

Other OPF messages

  • OPF-026 Found malformed property value: "…".
  • OPF-027 Undefined property: "…".
  • OPF-028 Undeclared prefix: "…".
  • OPF-021 Use of non-registered URI scheme type in href: "…".
  • OPF-029 The file "…" does not appear to match the media type …, as specified in the OPF file.
  • OPF-030 The unique-identifier "…" was not found.

Sources

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

FAQ

What does EPUBCheck OPF-025 mean?

EPUBCheck OPF-025 is an error message: “Property value list "…" is not allowed, only one value must be specified.” A metadata property that takes a single value was given a list of values. EPUBCheck names the list it found, and reading apps would not know which of the values to use.

Is OPF-025 an error?

OPF-025 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.