From Xojo Documentation
Property (As String )
| This property is only available on Windows and Linux platforms.
For cross-platform development, use ＃If...＃Endif with the Target... specifiers to make sure you will not attempt to use this property on an incompatible platform.
The string that appears in the Title bar. This property is ignored on Macintosh.
This example illustrates all the labelling properties of a FolderItemDialog.