Used to identify the source of the Account <1> code. This is especially useful if the account is a new account that the Respondent may not have setup yet in their system.
1 = BIC
2 = SID Code
3 = TFM (GSPTA)
4 = OMGEO (Alert ID)
5 = DTCC Code
99 = Other (custom or proprietary)
or any value conforming to the data type Reserved100Plus