| GDL Return Values | Explanation |
|---|---|
| GDL_ERROR | An error exists |
| GDL_FOUND | Feature found |
| GDL_NO_ADDRESSMATCH_FOUND | No address or ZIP5 data available |
| GDL_NOT_FOUND | Feature not found |
| GDL_NOT_IMPLEMENTED | Not implemented |
| GDL_NOT_LICENSED | GDL is not licensed |
| GDL_OK | Results are as expected |
| GDL_TEMP_PATH_ERROR | Temp path was incorrect |
| GDL_WRONG_TYPE | Wrong type passed |
| GDL_ZIP5_FILE_ERROR | ZIP5 file was incorrect |
| GDL_ZIP9_FILE_ERROR | ZIP9 file was incorrect |