ATPM 10.02 - ATPO: Outliner User Interfaces
http://www.atpm.com/10.02/atpo.shtml
>This is the way the Finder works, by the way: you can “collapse” an empty folder.
Looking at it with your dissenting opinion in mind, it's possible he is using 'Finder' to refer to the app that subsection is about. If that's true, however, it is weird how he capitalizes it like a name and uses a 'by the way' as if it were about something else.
If Finder were a general purpose name for a type of app it wouldn't be capitalized. So there must be a Company X Finder and an Apple Finder? He then refers to a 'pre-Panther Finder' right below adding to the mix.
So downgrade that part of my comment to 'some Apple application programmers even confuse triangles for bullets' if you aren't convinced. Weaker example, but I still don't see anything wrong with my reasoning that proceeded it.
I'll look into the 'show more' alternative. Maybe right underneath each heading would be good. That's somewhere you'd logically look for the content and it doesn't get in the way of reading the header like putting text where the symbol is now would.