After using ePub3-itizer to convert a 'no-fault-found' epub2 book to epub3, I've eliminated all the pink Validation Results (mostly involving image width being defined as %) except this one:
Code:
OEBPS/content.opf,127,9919,"Col: 92: ERROR(OPF-096): Non-linear content must be reachable, but found no hyperlink to "OEBPS/nav.xhtml"."
I've spent some time reading all 30 pages of this thread plus some others but don't understand how to fix the error. I take it that the reference to 'non-linear content' is down to the spine entry <itemref idref="navid" linear="no"/>.
I've seen KevinH's note in post #17 of this thread stating
Quote:
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" The created nav.xhtml is called is "nav.xhtml" not "toc.xhtml" and will be found right beside the content.opf file, not in the Text folder."
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I realise that was getting on for ten years ago and things, including plugins, change. But the Text folder is exactly where the nav.xhtml file is.
I understand that nav.xhtml is required by the spec, but for reading purposes, none of the content files need to link to it—that sort of communication is satisfied for the human reader by the existing HTML table of contents file (chapter3.xhtml in the book), which has links back from chapter headings. I note, too, that for Kindles, I can simply remove nav.xhtml from the spine to avoid it being displayed as a duplicate of the HTML toc.
If I understand correctly, the reading device will use and display nav.xhtml if it operates at the epub3 level. Otherwise, epub2 devices will use the everpresent toc.ncx file.
So, do I understand that epub3-itizer has created the nav.xhtml file as an orphan? Which files should link to it? What is the best solution to avoid this error message?