Coping with children.... (in Reading Lists)

Tom Morris has a few questions in regard to OPML Reading Lists -

How do they cope with children? I mean, if I make an outline, can I include sub-folders? If I include another outline, will NewsRiver (for instance) grab the contents of that outline and include them in my reading lists?

The good news it that Blogbridge copes fine, parsing down through the hierarchy as you'd expect, though you may encouter problems with OPML Editor as I did at first. However Kosso's new right-click 'Add feed URL' hack should solve that.