The classic case on installation manuals was a ZIP drive (Iomega) we got some time back. The installation instructions were on a ZIP disk that came with the drive, which of course you could not access until after you'd completed the installation.

In traditional "techspeak" a while back, the answer to all unsolvable riddles was "It's in Knuth." Knuth announced his intention to write a series of books to contain "everything about computing." He actually got through 3 or 4 books, and they were excellent; but he got interested in something else and the stuff everyone really wanted to know was "pending publication of next volume" - for about 20 years or so, at least.

John