This property indicates whether this button is the default button of the grid or reference set selector. A grid or reference set selector can only have one default button. The default button is triggered when clicking or double clicking a row. Whether a click or a double click triggers it depends on the 'default button trigger' property of the Data grid, Template grid or Reference set selector.
The default button is marked with a "(default)" suffix in the Modeler, so that you can easily spot it. In the screenshot below the Edit button is the default button and the Delete button has a button style 'Warning'.
Default value: False