Defines message type. ALWAYS THIRD FIELD IN MESSAGE. (Always unencrypted) Note: A "U" as the first character in the MsgType field (i.e. U1, U2, etc) indicates that the message format is privately defined between the sender and receiver. Valid values: *** Note the use of lower case letters *** 0 = Heartbeat 1 = Test Request 2 = Resend Request 3 = Reject 4 = Sequence Reset 5 = Logout 6 = Indication of Interest 7 = Advertisement 8 = Execution Report 9 = Order Cancel Reject A = Logon B = News C = Email D = Order – Single E = Order – List F = Order Cancel Request G= Order Cancel/Replace Request H= Order Status Request J = Allocation K = List Cancel Request L = List Execute M = List Status Request N = List Status P = Allocation ACK Q = Don’t Know Trade (DK) R = Quote Request S = Quote T = Settlement Instructions V = Market Data Request W = Market Data-Snapshot/Full Refresh X = Market Data-Incremental Refresh Y = Market Data Request Reject Z = Quote Cancel a = Quote Status Request b = Quote Acknowledgement c = Security Definition Request d = Security Definition e = Security Status Request f = Security Status g = Trading Session Status Request h = Trading Session Status i = Mass Quote j = Business Message Reject k = Bid Request l = Bid Response (lowercase L) m = List Strike Price