I'm guessing that you are using Saxon for processing. This issue was discussed a couple of weeks ago:
https://lists.oasis-open.org/archives/docbook-apps/201304/msg00025.html Bob Stayton Sagehill Enterprises [email protected] From: Lars Vogel Sent: Wednesday, April 17, 2013 1:52 PM To: DocBook Apps Subject: [docbook-apps] epub generation result has incorrect DocType Hello, I'm generating epub from Docbook input and getting during the validation one error and one warning with regards to the Doctype. [java] Epubcheck Version 3.0 [java] Validating against EPUB version 2.0 [java] ERROR: /home/vogella/workspace/docu/de.vogella.publishing/../output/epub/book.epub/OEBPS/content.opf: Obsolete or irregular DOCTYPE statement. The DOCTYPE can be removed. [java] WARNING: /home/vogella/workspace/docu/de.vogella.publishing/../output/epub/book.epub/OEBPS/toc.ncx: Irregular DOCTYPE: found '-//W3C//DTD XHTML 1.1//EN', expecting '<!DOCTYPE ncx PUBLIC "-//NISO//DTD ncx 2005-1//EN" "http://www.daisy.org/z3986/2005/ncx-2005-1.dtd";>'. My input looks simular to the XML file listed below. Any advice how to remove this error? I'm using DocBook XSL 1.77 for the transformation. Best regards, Lars <?xml version="1.0"?> <book> <bookinfo> <title>Java programming with the Eclipse IDE</title> <author> <firstname>Lars</firstname> <surname>Vogel</surname> </author> <copyright> <year>2007</year> <holder> Lars Vogel</holder> </copyright> <pubdate>17.02.2013</pubdate> <releaseinfo>Third edition </releaseinfo> <mediaobject role="cover"> <imageobject id="cover-image"> <imagedata fileref="images/cover.png" align="center" /> </imageobject> </mediaobject> </bookinfo> <part> <title>Eclipse Overview</title> <chapter> <title>Eclipse overview and terminology </title> <para> This chapter gives a short introduction into the Eclipse project and the Eclipse IDE. </para> </chapter> <part> </book>
