Omnibus Account = (not used and you can't enter a value via the web)
Tag 9121 = MemoField = T4 CustomerReference
Tag 9207 = Trading Account
Tag 439 = ICE ClearingFirm = T4 Member Allocation
Tag 440 = ICE ClearingAccount = T4 Trader Allocation
Tag 115 OnBehalfOfCompID (FTS|FTS) = Set as part of firm exchange driver configuration.
Tag 116 OnBehalfOfSubID (e.g. Busby|Busby, must be >= 3 characters long and must contain a "|") = Primary Login in User setup / Exchange Logins
Tag 144 OnBehalfOfLocationID (e.g. ISV-CTS|Trader, must be >= 3 characters long and must contain a "|") = Location in User Setup / Exchange Logins