At the very least, Gary Dexter’s collection of literary anecdotes — Why Not Catch-21?: The Stories Behind the Titles — sounds like a great stocking-stuffer. I hope the book is at least as entertaining as Nicholas Lezard’s review:
Dexter’s tone is consistently, and never irritatingly, droll. There are a few books that try to be funny about literature and don’t ever really get it right; Dexter always does. He has a fondness, and a gift, for the right kind of anecdote: such as the list of unsuitable words from The Sun Also Rises (“shit fuck bitch piss”) that the publisher Max Perkins wrote down. “Unfortunately, the heading on the pad was ‘Things to do today’. Charles Scribner came into Perkins’s office, saw the pad, and said to him: ‘You must be exhausted.'” Dexter, always conscientious in his search for the facts, adds a footnote telling a variant anecdote: Scribner says, “If you need reminding to do those things you’re in a worse state than I thought.”
I’d always heard that Heller’s title was originally Catch-18, but the number was changed to avoid confusion with the Leon Uris novel Mila 18, which had been published earlier in 1961. I guess now I’ll be able to cross-check that reference.