gtk:notebook-menu-label (notebook child)

notebook -- a gtk:notebook widget
child -- a gtk:widget child contained in a page of the notebook
menu -- a gtk:widget menu label, or nil for default

The gtk:notebook-menu-label function returns the menu label, or nil if the notebook page does not have a menu label other than the default notebook tab label. The (setf gtk:notebook-menu-label) function changes the menu label for the page containing the child.