Police have been officially advised to use their discretion in deciding how to enforce the ban on qat, a mild herbal stimulant, that has been widely used in Britain's Somali, Yemeni and Ethiopian communities. Official guidelines from the Association of Chief Police Officers tells constables that in applying a "three strikes" enforcement policy they should take into account that qat has "historically not been a controlled drug and was part of the culture of certain communities linked to the Horn of Africa." (See also: Stimulant khat banned as illegal class C drug in UK)