I know it's possible to filter a catalog item to be only applications,
say, by typing ".app" (or just "app", or "application", I think) in
the "Types:" field for the catalog item. What's the relevant string if
I want a catalog item to contain only folders? Specifically, my
Documents catalog item is too big, but my Documents folder is deeply
nested, so instead of just cutting off the indexing at a certain
point, I want QS to index all subfolders but ignore files, and then
I'll get at the files with -> or /.
