[rules-users] Rule Templates - Docs & Examples?

I am trying to research using a rule template driven by data from a spreadsheet, rather than using a straight decision table. I understand I need to use the ExternalSpreadsheetCompiler but am finding a distressing lack of information about the template format. The 5.0 docs seem to have mistakes; the code example for that section looks to have been cut & pasted from another section and does not match the text description of what is going on. Using google, the best I could find was a blog posting from Steven Williams on Aug 26, 2008: http://blog.athico.com/2008/08/drools-rule-templates.html In this blog posting, he said it was the first of 3 examples from the drools-examples project. But I could not find any additional blog postings by him on this subject. Does anyone know of additional documentation or examples on how rule templates work? Specifically, how to do optional columns, and array columns, similar to how the built in decision tables feature works? Adam