Creating <keyval> files is not particularily difficult if you have a XML intelligent editor. If you use the following as your initial starting point, a XML intelligent editor (jEdit - Open Source Text Editor) should be able to guide you as to what tags and attributes are appropriate within your document. The minimal form (a configuration with zero key/value definitions) is shown below:

<?xml version="1.0"?>

<!DOCTYPE keyval PUBLIC
   "-//VAISALA//DTD KeyValue XML V1.0.0//EN"
   "http://www.mekwin.com/vaisala/xml/dtd/keyval/keyval_1_0_0.dtd">

<keyval class="NAME" namespace="lp">

</keyval>

Paul needs to fill in the rest of the information here, or find a DTD to DocBook utility to generate something.