It is mainly used to easily place individual language links inside menu items. For example you can create a menu item with URL = #, Navigation Label = Spanish and Description = {bbackup_94402fb9ba80f392e0976ece85f92b2b876bfcaed8d83250cc06083f7139c7d9}1$s[gt-link lang="es" label="Spanish" widget_look="flags_name"]{bbackup_94402fb9ba80f392e0976ece85f92b2b876bfcaed8d83250cc06083f7139c7d9}2$s and a single menu item will appear to change the language to Spanish.