A prison commissary is a store within a correctional facility where inmates can purchase products such as hygiene items, snacks, writing instruments, and other authorized items. Typically, inmates are not allowed to possess cash, so they make purchases through an account with funds from money contributed by friends, family members, or earned as wages. Most prisons set a maximum limit of funds that can be spent by each inmate on commissary, and significant price markups are common in prison commissaries, although some prison systems set maximum markups. Inmates with good behavior are allowed to use their trust fund money to purchase additional supplies from the prison "store" or commissary. The right to purchase items from the commissary is a privilege that can be restricted if there are behavioral problems. Prisoners look forward to commissary day, which is typically once every two weeks, and they can buy items such as coffee, instant soup, chips, cookies, canned foods, shampoo, soap, toothpaste, writing paper, and stamps. With approval, prisoners can also buy things like hot pots, clocks, fans, typewriters, shoes, underclothing, and basic over-the-counter medications. Prison commissary is a privilege that is often taken away for infractions.