They had to have special permission to travel there or leave, and anyone seeking residency was required to undergo vetting by the NKVD and its successor agencies.
De skulle have specialtilladelse for at rejse dertil og for at tage derfra, og enhver, som ønskede at bosætte sig der, skulle gennemgå kontroller af sikkerhedstjenesten NKVD og efterfølgeren KGB.