This annual publication provides technical information on the licit movement of the internationally controlled narcotic drugs. The relevant 1961 Convention establishes strict controls on the cultivation of opium poppy, coca bush, cannabis plant and their products, which, in the Convention, are described as ""narcotic drugs""; (although cocaine is a stimulant drug rather than one that induces sleep). Control is exercised over 136 narcotic drugs, mainly natural products, such as opium and its derivatives, morphine, codeine and heroin, but also synthetic drugs, such as methadone and pethidine, as well as cannabis and coca leaf. The production and distribution of controlled substances must be licensed and supervised, and governments must provide estimates and statistical returns on the quantities of drugs required, manufactured and utilized and the quantities seized by police and customs officers.