Used to specify what identifier, provided in order depth market data, to use when hitting (taking) a specific order.
| Code | Meaning |
|---|---|
| 0 | Secondary order ID |
| 1 | Order ID |
| 2 | Market data entry ID |
| 3 | Quote entry ID |
| 4 | Original order ID |
| 5 | Quote ID |
| 6 | Quote request ID |
| 7 | Previous order identifier |
| 8 | Previous quote identifier |
| 9 | Parent order identifier |
| A | Manual order identifier |