| 0 | heartbeat |
| 1 | test request |
| 2 | resend request |
| 3 | reject |
| 4 | sequence reset |
| 5 | logout |
| 6 | indication of interest |
| 7 | advertisement |
| 8 | execution report |
| 9 | order cancel reject |
| A | logon |
| B | news |
| C | email |
| D | order single |
| E | order list |
| F | order cancel request |
| G | Order Cancel/Replace Request |
| H | order status request |
| J | allocation |
| K | list cancel request |
| L | list execute |
| M | list status request |
| N | list status |
| P | allocation ack |
| Q | dont know trade |
| R | quote request |
| S | quote |
| T | settlement instructions |
| V | market data request |
| W | market data snapshot |
| X | market data incremental refresh |
| Y | market data request reject |
| Z | quote cancel |
| a | quote status request |
| b | mass quote acknowledgement |
| c | security definition request |
| d | security definition |
| e | security status request |
| f | security status |
| g | trading session status request |
| h | trading session status |
| i | mass quote |
| j | business message reject |
| k | bid request |
| l | bid response |
| m | list strike price |