Preference File XML Vocabulary
The preferences file, distributed with blog, is actually used by another package which is distributed with blog (nb.jar). It satisfies the needs of that package's Preferences class (feel free to use it under the same license as blog). The preference file is written in XML, which means it uses a specific XML vocabulary. I have not created a DTD for this vocabulary because I am lazy and didn't see any reason to (only the Preferences class uses it). However, in plain english, this is the vocabulary:
<Category name="the name of the category">
<Preference name="name of preference" value="whatever value you give it" />
Simple, huh? Yes, it was designed to be very human-readable so that it could be used as a preference file, likely to be touched by human *hands*. You don't even need to alter the category or the preference except to put your value in the preference's value attribute.