gtk:check-button-use-underline (object)

object -- a gtk:check-button widget
setting -- a boolean whether an underline in the text indicates the next character should be used for the mnemonic accelerator key

The accessor for the use-underline slot gets or sets whether underlines in the label indicate mnemonics.

If the setting is true, an underscore character indicates a mnemonic accelerator key. This behavior is similar to the use-underline property of the gtk:label widget.