ShadowFilters.xml structure

All,
  I've been digging around the message archives and the website, but can't seem to find anything that documents the structure of the Shadow Plan filters file.  I've switched to a non-palm OS phone, but still love/heavily use SP on my Windows desktop.  I need to create some new filters, but I'm struggling to figure out the exact syntax of the filters file so that I can modify it.

  Does anyone have a document that describes the fields and allowed values?  If it's already posted and I just missed it, please point me at it?

Thanks in advance,

Eric