I'm in the process of summarizing some Supreme Court opinions for an appellate journal. And I came across what is perhaps the best passage in the history of Supreme Court opinions. It's Scalia writing in Republic of Iraq v. Beaty:
But the whole value of a generally phrased residual clause, like the one used in the second proviso, is that it serves as a catchall for matters not specifically contemplated—known unknowns, in the happy phrase coined by Secretary of Defense Donald Rumsfeld. Pieces of Intelligence: The Existential Poetry of Donald H. Rumsfeld 2 (H.Seely comp. 2003).
That's good stuff.