360T GTX Maker, formerly run by Gain Capital, has a FIX API that allows liquidity providers to price sweepable or full amount streams in NY4, LD4, and TY3. Their FIX API for market makers includes a non-standard feature where inbound orders contain a clOrdID (client order ID) value that’s the same identifier as the quoteID generated by the maker. This means that if two different takers attempt to execute on the same quote, both inbound new order single messages will have the same clOrdID.
According to FIX Protocol, the clOrdID must have guaranteed uniqueness over the duration of a single trading day. Under ordinary circumstances, receiving the same clOrdID multiple times in a single trading day is not to be expected, may be flagged as a duplicate order message, and possibly lead to other problems such as NOP or STP booking related issues.
MarketFactory handles this situation by taking the execID from the order message, which is always unique, and passing this to the market maker in the clOrdID field. In other words, when MarketFactory normalizes the message, it is ensured that the clOrdID received by the end client is always unique, thus avoiding potential problems caused by receiving multiple clOrdIDs of the same value.