DTD Entities

There are two conditions for including a part using DTD entities:

• The master document should declare the DTD to be used, while the external entities should declare the XML sections to be referred;
• The document containing the section must not define again the DTD.

<?xml version="1.0" encoding="UTF-8"?> 
<!DOCTYPE book SYSTEM "../xml/docbookx.dtd" [ 
<!ENTITY testing SYSTEM "testing.xml" > ]
> 
<book> 
<chapter> ...

The referred document looks like this:

<section> ... here comes the section content ... </section>