906 Level Number
The level of the control segment in the interchange order table of the electronic form
- Type
 - Identifier (ID)
 - Length
 - Min 1 / Max 1
 - Codes
 | Code | Description | 
|---|
|  0 | Application Data Segment | 
|  1 | Application Control Segment (e.g., ST/SE) | 
|  2 | Group Control Segment (e.g., GS/GE) | 
|  3 | Interchange Control Segment (e.g., ISA/TA1/IEA) |