[sgirsberger]

Embarrassing question, but I need confirmation.

I have a lovely EPUB that works great on an iPad, a NOOK Color, an iPhone, and in the Kindle Previewer.

It passes the ePubChecker preflight with no warnings or errors.

However, it yields “bad value for attribute "id"” and “bad value for attribute “idref” in 66 lines of the content.opf file.

It also yields “bad value for attribute "id"” for 33 of the book's HTML files.

These files are named sequentially, 01.html, 02.html, etc. They're the individual chapter files. The other files in the book have functional names—copyright, preface, etc.

I have a bad feeling that the digits in the file names are causing the problem—is this correct? Or would it be an intervening path?

Here are samples of the ERROR syntax (path names omitted):

ERROR: . . . /OEBPS/content.opf(56): bad value for attribute "id"
ERROR: . . . /OEBPS/content.opf(103): bad value for attribute "idref"
ERROR: . . . /OEBPS/Text/01.html(12): bad value for attribute "id"

Your advice is greatly appreciated!