One of my important but underpaid field agents has pointed out that when Gussie Fink-Nottle is arrested for swimming in the fountain in Trafalgar square he gives his name as Alfred Duff Cooper.
My agent is reading Evelyn Waugh's letters to Nancy Mitford. Evelyn says that the pseudonym is notable because Wodehousian characters in these circumstances usually use Trotsky, Lenin or similar.*
*Another of my IBUFAs has explained this whole affair in the comment below, which I strongly recommend. His generous assumption that I knew it already is kind. Life is learning.