Vague guessing (fortunately haven't had to seriously diddle w/XML in years) maybe helpful: Your first item is a "processing instruction". Looks like XML::Rules sits on top of XML::Parser::Expat which says that it emits "Proc" events or "Comment" events when encountering what you mention so if there's some way to wire the former module up to be called for the latter items that might be what you want. Alternately you may need to resort to using that lower level module directly.

Edit: event phrasing.