TextArea.SelectionPlain

From Xojo Documentation

Property (As Boolean )
aTextArea.SelectionPlain = newBooleanValue
or
BooleanValue = aTextArea.SelectionPlain

New in 2019r2

Supported for all project types and targets.

If True, the selected text is plain. If the selected text is styled (e.g., Bold), setting SelectionPlain to True changes it to Plain.