Tag 66
ListID
Abbreviation:
Description
Customer assigned listUnique identifier for list as assigned by institution, used to associate multiple individual orders. Uniqueness must be guaranteed within a single trading day. Firms which generate multi-day orders should consider embedding a date within the ListID field to assure uniqueness across days.
Wire Format & Usage Example
Single field (key=value)
66=A
In a FIX message (ExecutionReport)
8=FIX.4.4 | 9=... | 35=8 | 49=SENDER | 56=TARGET | 34=1 | 52=20240101-09:30:00.000 | … | 66=A | … | 10=...
Fields are delimited by SOH (ASCII 0x01), shown here as " | ". The highlighted field 66=A is this field's position in the message.