Hi,
I wrote this specs for the exception and warning formats: http://docs.moodle.org/dev/Errors_handling_in_web_services

I also added some comments in the discussion page: http://docs.moodle.org/dev/Talk:Errors_handling_in_web_services

I think we kind of agreed about the exception format but no one that I know reviewed the warnings structure yet. Note that warnings format is based on Paul's formatas I mentioned in the discussion page. You want to have a look to his format.

I need +1s then I can spread the words around all web service contributors