ExtraCheckBoxText is used to label the extra checkbox.
Namespace: Autodesk.Revit.UI
Assembly: RevitAPIUI (in RevitAPIUI.dll) Version: 17.0.0.0 (17.0.1090.0)
Since: 2017
Syntax
Remarks
If ExtraCheckBoxText is set, a checkbox with the text will be shown. You can get the response of checkbox by checking the return value of the WasExtraCheckBoxChecked() method.