Type: String
Used to identify the event or source which gave rise to a message.
Valid values will be based on an exchange’s implementation.
Example values are:
"MQM" (originated at Firm Back Office)
"Clear" (originated in Clearing System)
"Reg" (static data generated via Register request)
Added in protocol FIX.4.4 (EP 5)
See in: FIX.5.0, FIX.5.0SP1, FIX.5.0SP2.