def- you're right, there is no way to tell which order on the tape belongs to a customer. However, I have been on the trading and trading firm end of trades, as Series 24 as well. Every single order that goes to the market (Nasdaq and listed) has an order id. This number is specific to the customer that entered it, that number is generated by the b/d, and is then it's read by the respective exchange (Nasdaq and NYSE has 8 digit a/n #), with another number added to it. The purpose of two ID #'s is, regardless of what side is responsible, the either side can track down the trade, and get an answer for the client. The only one should enter a dupe, is the trade desk. Now speaking from Nasdaq, the clerk uses Nasdaq NWII, to enter the order ID in question which is on the customer's screen. Order ID either shows "Sent" or "Received" by the exchange. Sent means the order never got there, in most cases the b/d eats the trade, if received by the exchange and no subsequent report was sent, b/d will eat and fight with clear-thru or exchange rep to get it back. I did not know these were minis until I looked at image. However, one thing is for sure, if a customer is allowed to enter a duplicate order on same side, there is a fundamental problem with the software, you can't blame Globex, your the IB (introducing broker) for the trade. What do you expect a customer to do when they click and an order goes off into the abyss, wait? Until the flaw is fixed, the problem wil continue, and thats a shame, IB is branding nicely.