Purge Acknowledgement Message Fields

A Purge Acknowledgment message is an unsequenced message sent when a Purge Orders message requesting an order purge has completed canceling all individual orders.

Multiple Purge Acknowledgment messages will be sent in response to Purge Order message requests for multi-unit orders (MassCancelInst, 2nd character = I). An acknowledgement message will be sent for each matching unit followed by a final acknowledgement containing the total number of orders cancelled due to the purge request across all matching units. This final acknowledgment will have a SourceMatchingUnit value of 0.