An order (limit order) that is not revealed to the public- i.e., it is not displayed in the market system. However, non-displayed orders remain placed for potential execution against all incoming orders until executed in full or cancelled. An example of such an order is the minimum quantity orders (MQOs) (which, once posted on the exchange book, remain always non-displayed). Non-displayed orders are not displayed in the central limit order book (hence, are not visible) but are fully integrated into the existing order book on each exchange, where the new non-displayed orders will be allowed to interact with displayed orders and other non-displayed orders.

Non-displayed orders can be in the form of undisclosed orders pegged to the mid-point of the national best bid or offer (non-displayed midpoint) or limit orders where price and volume  are undisclosed (non-displayed limit orders, or non-displayed limit).

Non-displayed orders are also known as dark orders.