The explanation reads: ""Rackets," as known in prison camps, consisted of acquiring food and selling same to the few who were able to pay for it, either with cigarettes or personal belongings. Fortunately, however, the majority of camps were too well organised to allow this practice to develop."

 

This illustration is taken from "Handle With Care" by R. Anderson and D. Westmacott, a book of sketches made by Prisoners of War.