To uniquely identify interchange control structures
| Position | Element | Name | Type | Min/Max | Repeat | |
|---|---|---|---|---|---|---|
| 1 | I44  | Reported Start Segment ID | Opt | Alphanumeric | 2/3 | AtMax 1 | 
| 2 | I45  | Reported Control Number | Opt | Alphanumeric | 1/14 | AtMax 1 | 
| 3 | I46  | Reported Date | Opt | Alphanumeric | 1/8 | AtMax 1 | 
| 4 | I47  | Reported Time | Opt | Alphanumeric | 1/8 | AtMax 1 | 
| 5 | I48  | Reported Interchange Sender ID Qualifier | Opt | Alphanumeric | 1/4 | AtMax 1 | 
| 6 | I49  | Reported Sender ID | Opt | Alphanumeric | 1/35 | AtMax 1 | 
| 7 | I50  | Reported Interchange Receiver ID Qualifier | Opt | Alphanumeric | 1/4 | AtMax 1 | 
| 8 | I51  | Reported Receiver ID | Opt | Alphanumeric | 1/35 | AtMax 1 | 
| 9 | I52  | First Reference ID Qualifier | Opt | Alphanumeric | 1/4 | AtMax 1 | 
| 10 | I53  | First Reference ID | Opt | Alphanumeric | 1/14 | AtMax 1 | 
| 11 | I54  | Second Reference ID Qualifier | Opt | Alphanumeric | 1/4 | AtMax 1 | 
| 12 | I55  | Second Reference ID | Opt | Alphanumeric | 1/14 | AtMax 1 | 
| 13 | I61  | Interchange Message Direction Code | Opt | ID | 1/1 | AtMax 1 | 
| 14 | I64  | Reported Group or Transaction Identifier | Opt | Alphanumeric | 2/6 | AtMax 1 |