SettlType Field
Regular is defined as the default settlement period for the particular security on the exchange of execution.
In Fixed Income the contents of this field may influence the instrument definition if the SecurityID (48) is ambiguous. In the US an active Treasury offering may be re-opened, and for a time one CUSIP will apply to both the current and when-issued securities. Supplying a value of 7 clarifies the instrument description; any other value or the absence of this field should cause the respondent to default to the active issue.
Valid values:
0 = Regular
1 = Cash
2 = Next Day (T+1)
3 = T+2
4 = T+3
5 = T+4
6 = Future
7 = When And If Issued
8 = Sellers Option
9 = T+ 5
A = T+1 (Removed in FIX 4.4, use "2 = Next Day (T+1)" value)