In January 1948 Kruglov and Abakumov presented for Stalin's signature a memorandum that significantly toughened the Gulag conditions for political prisoners. Many of those who had been arrested at the height of the Great Purge in 1937-38 and given 10-year prison sentences and managed to survive their time in Gulag were due for release. The Abakumov-Kruglov memorandum, approved by Stalin, authorized the creation of a special system of labor camps for political prisoners. MVD was authorized to hold, when deemed necessary, such political prisoners beyond the expiration dates of their sentences and to send them to the so-called administrative exile (административная ссылка) in the cases where formal release did occur. Thereafter, both significant terms of administrative exile, given after the completion of the nominal prison sentences, and significant delays of the nominal release after such completion of sentences (referred to as "overstaying one's welcome"), became standard MVD practices in running the Gulag system.