To indicate the beginning of the Purchase Order Transaction Set and transmit identifying numbers and dates
| Position | Element | Name | Type | Min/Max | Repeat | |
|---|---|---|---|---|---|---|
| 1 | 353 | Transaction Set Purpose Code | Mandatory | ID | 2/2 | 1 |
| 2 | 92 | Purchase Order Type Code | Mandatory | ID | 2/2 | 1 |
| 3 | 324 | Purchase Order Number | Mandatory | Alphanumeric | 1/22 | 1 |
| 4 | 328 | Release Number | Opt | Alphanumeric | 1/30 | 1 |
| 5 | 373 | Date | Mandatory | Date | 8/8 | 1 |
| 6 | 367 | Contract Number | Opt | Alphanumeric | 1/30 | 1 |
| 7 | 587 | Acknowledgment Type | Opt | ID | 2/2 | 1 |
| 8 | 1019 | Invoice Type Code | Opt | ID | 3/3 | 1 |
| 9 | 1166 | Contract Type Code | Opt | ID | 2/2 | 1 |
| 10 | 1232 | Purchase Category | Opt | ID | 2/2 | 1 |
| 11 | 786 | Security Level Code | Opt | ID | 2/2 | 1 |
| 12 | 640 | Transaction Type Code | Opt | ID | 2/2 | 1 |