xnoteset is a wrapper for one or more xnote elements. The namespace is "http://refdb.sourceforge.net/namespaces/xnote".
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE xnoteset PUBLIC "-//Markus Hoenicka//DTD Xnote V1.2//EN" "http://refdb.sourceforge.net/dtd/xnote-1.2/xnote.dtd" [
<!ENTITY lt "<">
<!ENTITY gt ">">
<!ENTITY amp "&">
]>
<xnoteset xmlns="http://refdb.sourceforge.net/namespaces/xnote">
<xnote>
...
</xnote>
<xnote>
...
</xnote>
</xnoteset>