OPF-086 is reported as warning by default. The EPUB is still valid, but something is likely to cause problems in some reading apps. EPUBCheck exits with 0 unless you pass --failonwarnings.

EPUBCheck · Package document (OPF)

`OPF-086`

Updated: Nov 3, 2026

EPUBCheck OPF-086 is a warning message: “Property "…" is deprecated. Consider using … instead.” A metadata property is deprecated; EPUBCheck names the property and the replacement to use.

The official message

Property "%1$s" is deprecated. Consider using %2$s instead.

Variants

default: a custom prefixed property
marc21xml-record: the "record" keyword and the media-type "application/marcxml+xml"
mods-record: the "record" keyword and the media-type "application/mods+xml"
onix-record: the "record" keyword with the properties attribute value "onix"
xml-signature: no signature-identifying link
xmp-record: the "record" keyword

Default severity: Warning. The EPUB is still valid, but something is likely to cause problems in some reading apps. EPUBCheck exits with 0 unless you pass --failonwarnings.
EPUBCheck version: 5.4.0

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

Typical causes

Package documents written for older EPUB 3 versions.

How to fix it

Replace the property with the one EPUBCheck suggests, or remove it if it is no longer needed.

Terms used here

Other OPF messages

OPF-086b epub:type value "…" is deprecated. Consider using … instead.
OPF-085 "dc:identifier" value "…" is marked as a UUID, but is an invalid UUID.
OPF-088 Unrecognized epub:type value "…".
OPF-090 It is encouraged to use MIME media type "…" instead of "…".
OPF-091 The item href URL must not have a fragment identifier.

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