People refer to each other in the form "Comrade-surname," which is inappropriate among colleagues. Dyatlov's subordinates would have called him "Dyatlov" among themselves and "Anatoly Stepanovich" (his first name and patronymic) when addressing him directly, rather than "Comrade Dyatlov." However, it is likely the writers decided against using the correct forms of address to avoid confusion with non-Russian viewers, who might think, for example, that Stepanovich is Dyatlov's surname.