| Constant | Value | Description |
| vbWrongFormat | 1 | Another application requested data in wrong format |
| vbDDESourceClosed | 6 | Destination application attempted to continue after source closed |
| vbTooManyLinks | 7 | All source links are in use |
| vbDataTransferFailed | 8 | Failure to update data in destination |
| Constant | Value | Description |
| vbLinkNone | 0 | None |
| vbLinkSource | 1 | Source (forms only) |
| vbLinkAutomatic | 1 | Automatic (controls only) |
| vbLinkManual | 2 | Manual (controls only) |
| vbLinkNotify | 3 | Notify (controls only) |
| Constant | Value | Description |
| vbHot | 1 | Hot (controls only) |
| vbServer | 1 | Server (forms only) |
| vbCold | 2 | Cold (controls only) |