With his greeting of 'Evenin' all', Dixon of Dock Green embodied the values of the solid, commonsense copper.
But his reassuring salutation, which began each episode of the classic police TV drama from 1955 to 1976, is one which today's real-life officers should be wary of using.
According to one force's official guidelines, it could confuse people from different cultural backgrounds.
Warwickshire Police's handbook Policing Our Communities, issued to every member of its staff, gives advice on communicating with people from different ethnic groups in a section entitled Communication, Some Dos & Don’ts.
It states: 'Don't assume those words for the time of day, such as afternoon or evening, have the same meaning.'
A force spokesman explained: 'Terms such as afternoon and evening are somewhat subjective in meaning and can vary according to a person's culture or nationality. In many cultures the term evening is linked to time of day when people have their main meal of the day.