This could include a child of as young as three who says "yuk" in response to being served unfamiliar foreign food.
The guidance by the NCB is designed to draw attention to potentially-racist attitudes in youngsters from a young age.
It alerts playgroup leaders that even babies can not be ignored in the drive to root out prejudice as they can "recognise different people in their lives".
The 366-page guide for staff in charge of pre-school children, called Young Children and Racial Justice, warns: "Racist incidents among children in early years settings tend to be around name-calling, casual thoughtless comments and peer group relationships."
It advises nursery teachers to be on the alert for childish abuse such as: "blackie", "Pakis", "those people" or "they smell".
The guide goes on to warn that children might also "react negatively to a culinary tradition other than their own by saying 'yuk'".
Staff are told: "No racist incident should be ignored. When there is a clear racist incident, it is necessary to be specific in condemning the action."
Warning that failing to pick children up on their racist attitudes could instil prejudice, the NCB adds that if children "reveal negative attitudes, the lack of censure may indicate to the child that there is nothing unacceptable about such attitudes".
Nurseries are encouraged to report as many incidents as possible to their local council. The guide added: "Some people think that if a large number of racist incidents are reported, this will reflect badly on the institution. In fact, the opposite is the case."
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