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EPUBCheck · Navigation document

EPUBCheck NAV-011: nav entries out of order

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EPUBCheck NAV-011 is a warning message: “"…" nav must be in reading order; link target "…" is before the previous link’s target in … order.” The entries of a nav are not in reading order. A link points to a place before the previous entry's target, in spine order or within a document, and EPUBCheck names both.

The official message

"%1$s" nav must be in reading order; link target "%2$s" is before the previous link’s target in %3$s order.

Variants

  • spine: spine
  • document: document
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

  • A table of contents edited by hand whose order no longer matches the spine.
  • A chapter moved in the spine without updating the table of contents.
  • A page list built from page numbers sorted as text (1, 10, 11, 2).

How to fix it

  1. Find the entry EPUBCheck reports and compare it with the spine order in the package document.
  2. Reorder the nav entries to match the spine and the order inside each document, or fix the spine if it is the spine that is wrong.
  3. Rebuild the EPUB and run EPUBCheck again to confirm the message is gone.

When it's not this

If an entry links to a remote website, the message is NAV-010.

Terms used here

Other NAV messages

  • NAV-010 "…" nav must not link to remote resources; found link to "…".
  • NAV-006 Content documents contain "figure" elements but the Navigation Document does not have a listing of figures (epub:type="loi").
  • NAV-003 The Navigation Document must have a page list when content document(s) contain page breaks (epub:type="pagebreak").
  • NAV-001 The nav file is not supported for EPUB v2.

Sources

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

FAQ

What does EPUBCheck NAV-011 mean?

EPUBCheck NAV-011 is a warning message: “"…" nav must be in reading order; link target "…" is before the previous link’s target in … order.” The entries of a nav are not in reading order. A link points to a place before the previous entry's target, in spine order or within a document, and EPUBCheck names both.

Is NAV-011 an error?

NAV-011 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.