Taken from Bisac X12 v3060
Header Segments
| ST | Transaction Set Header |
Detail Segments
| AK1 | Functional Group Response Header |
| AK2 | Transaction Set Response Header |
| AK5 | Transaction Set Response Trailer |
| AK9 | Transaction Group Response Trailer |
Summary Segments
| SE | Transaction Set Trailer |
ST Transaction Set Header
| Element | Name | Value |
| ST | Segment Identifier | ST |
| ST01 | Transaction Set ID | 997 |
| ST02 | Transaction Set Control Number | Assigned by Sender (unique) |
AK1 Functional Group Response Header
| Element | Name | Value |
| AK1 | Segment Identifier | AK1 |
| AK101 | Functional Identifier Code | PO for Purchase Order |
| AK102 | Group Control Number | Control Number from the original order (GS06) |
AK2 Transaction Set Response Header
| Element | Name | Value |
| AK2 | Segment Identifier | AK2 |
| AK201 | Transaction Set Identifier Code | 850 for Purchase Order |
| AK202 | Transaction Set Control Number | Control Number from the original order (??) |
AK5 Transaction Set Response Trailer
| Element | Name | Value |
| AK5 | Segment Identifier | AK5 |
| AK501 | Transaction Set Acknowledgement Code | �A� for accepted �R� for rejected |
AK9 Functional Group Response Trailer
| Element | Name | Value |
| AK9 | Segment Identifier | AK9 |
| AK901 | Functional Group Acknowledgement Code | �A� for accepted �R� for rejected |
| AK902 | Number of Transaction Sets Sent | |
| AK903 | Number of Received Transaction Sets | |
| AK904 | Number of Accepted Transaction Sets |
SE Transaction Set Trailer
| Element | Name | Value |
| SE | Segment Identifier | SE |
| SE01 | Number of Lines | Number of lines in ST transaction (including ST and SE lines) |
| SE02 | Transaction Set Control Number | Assigned by Sender (unique), (same as ST02) |