Request price quotation or RPQ is a long-standing IBM designation for a product or component that is potentially available, but that is not on the "standard" price list.[1][2] Typical RPQ offerings are custom interfaces, hardware modifications, research or experimental systems, or variable-cost items. In the days of IBM's large mainframes, e.g. the System/360 and System/370 series, many unusual features were flagged as "RPQ".
A special-order software item is known as a Programming Request Price Quotation or PRPQ.