Playing on Elite with all in-game difficulties disabled (except camera shake) on certain vehicles the icon to display squad leader/commander of a group is always displayed or shows after opening and closing the map. From a bit of digging in the configs have noticed this applies to vehicles that have a turret enabled eg. the Hunter doesn't have this but the HMG and GMG variants do. Haven't tested fully but would imagine it's the same for other difficulty settings where the group HUD indicators are turned off.