Resale price maintenance (RPM) or, occasionally, retail price maintenance is the practice whereby a manufacturer and its distributors agree that the distributors will sell the manufacturer's product at certain prices (resale price maintenance), at or above a price floor (minimum resale price maintenance) or at or below a price ceiling (maximum resale price maintenance). If a reseller refuses to maintain prices, either openly or covertly (see grey market), the manufacturer may stop doing business with it. Resale price maintenance is illegal in many jurisdictions.