A method of operating a plurality of mobile units

In a method for operating a plurality of mobile units (11, 12, 13, 14), in which at least at times, a formation is constituted by a plurality of mobile units, each mobile units each have at least one signal output element (110, 120, 130 , 140) on. Here, it is made by the individual mobile units of the formation of a concerted output communication signals via the signal output elements to the environment.