In
Neal Stephenson's book
Cryptonomicon, there is a reference to a
military manual titled "Tactical Negro Impersonation Volume III: Negroes of the Caribbean". It gives advice on how a ship's crew should behave to fool passing
submarines into thinking that their ship is crewed by dark-skinned
natives and not white
US Navy personnel.
I don't know if this book actually existed, or if it was something Neal made up when writing his
novel. The fact that I can't find any reference to this on the
Internet (other than a few links on
E2) indicates it is probably fictitious -- or
classified.