I caught up with the meaning of TWS - Trader Workstation at IB.
Reference DOM, I noticed at the IB website this:
"Open Market Depth/Level II Order on Trading Page.
After you create an order from either the Market Depth or Level II window, the trading page that holds the order will pop in front of the Market Depth or Level II window to make it easy for you to review the order parameters and transmit the order."
What is IF1 and IF2? Someone must know.
Anyone please?