Simple Sabotage Field Manual: (Declassified)

This Simple Sabotage Field Manual, a genuine guide from the Second World War, states that its purpose is to "characterize simple sabotage, to outline its possible effects, and to present suggestions for inciting and executing it." Among the other fine pieces of advice in this handy volume, one is encouraged to "switch address labels on enemy baggage", "let cutting tools grow dull", "forget to provide paper in toilets", and "change sign posts at intersections and forks; the enemy will go the wrong way and it may be miles before he discovers his mistakes."