| 1 |
| Parent |
| A code to indicate a parent relationship. |
| 2 |
| Child |
| A code to indicate a child relationship. |
| 3 |
| Peer, internal |
| A code to indicate an internal peer relationship. |
| 4 |
| Peer, external |
| A code to indicate an external peer relationship. |
| 5 |
| Finish to start constraint |
| A code to indicate a finish to start constraint relationship. |
| 6 |
| Start to start constraint |
| A code to indicate a start to start constraint relationship. |
| 7 |
| Finish to finish constraint |
| A code to indicate a finish to finish constraint relationship. |
| 8 |
| Start to finish constraint |
| A code to indicate a start to finish constraint relationship. |