DocBook 5: The Definitive Guide

Understanding Validation Errors

Every validator produces slightly different error messages, but most indicate exactly (at least technically^[2]) what is wrong and where the error occurred. With a little experience, this information is all you’ll need to quickly identify what’s wrong.

In the rest of this section, we’ll look at a number of common errors and the messages they produce in MSV. We’ve chosen MSV because it generally produces informative error messages.

Character Data Not Allowed Here

Out-of-context character data is frequently caused by a missing start tag, but sometimes it’s just the result of typing in the wrong place!

<chapter xmlns="http://docbook.org/ns/docbook" version="5.0">
<title>Test Chapter</title>
<para>
This is a paragraph in the test chapter. It is unremarkable in
every regard. This is a paragraph in the test chapter. It is
unremarkable in every regard. This is a paragraph in the test
chapter. It is unremarkable in every regard.
</para>
You can't put character data here.
<para>
<emphasis role="bold">This</emphasis> paragraph contains
<emphasis>some <emphasis>emphasized</emphasis> text</emphasis>
and a <superscript>super</superscript>script
and a <subscript>sub</subscript>script.
</para>
<para>
This is a paragraph in the test chapter. It is unremarkable in
every regard. This is a paragraph in the test chapter. It is
unremarkable in every regard. This is a paragraph in the test
chapter. It is unremarkable in every regard.
</para>
</chapter>

java -jar msv.jar docbook.rng ...