This message is used to request the cancellation of the remaining quantity of an existing order. The Order Cancel/Replace Request <35=G> should be used to reduce an order's quantity.
The request will only be accepted if the order can be successfully pulled from the exchange without executing.
Each request is assigned a ClOrdID (11) and is treated as a separate entity. The ClOrdID (11) assigned to the request must be unique amongst the ClOrdID (11) assigned to regular orders and replacement orders.
If rejected, the ClOrdID (11) of the request will be sent in the Order Cancel Reject <35=9> message, as well as the ClOrdID (11) of the actual order in the OrigClOrdID (41) field.
An immediate response to this message is required. It is recommended that an Execution Report <35=8> with ExecType (150) = "Pending Cancel" be sent unless the request can be immediately accepted or rejected.