I’ve always liked books like this which were never intended to be sold; they often make fascinating reading. This one, from 1920s Berlin, entitled simply ‘Spitzel-Almanach. Unverkäuflich …’ (‘Spy Almanac. Not for sale’) and bound in plain paper wrappers, was an internal publication of the German Communist Party and gives details of all the known spies and informers employed against the Party at the time. A brief history of the spies, their methods, organization, finance, techniques on exposing them and a short bibliography is followed by over 90 pages listing the known spies and fraudsters who have had run-ins with the Party. The book was only to be used by senior members of the Party and, according to the introduction, was never intended to be the personal possession of any single Party member.