CIA manual of trickery and deception

It includes deceptions such as spiking drinks, pocketing small objects and tying shoelaces to communicate in code.

The CIA ordered copies destroyed in the 1970s, but one survived. It has been republished as The Official CIA Manual of Trickery and Deception.

Among several deceptions detailed in the book, it instructs spies on how to tie their shoelaces to signal other spies - "I have information", "Follow me", or "I have brought another person".

It also shows operatives how to conceal a doping pill in a matchbook, then covertly drop it into a person's drink while distracting them by lighting their cigarette. SOURCE