| Subject | English | Russian |
| tech. | letter code | код литеры |
| tech. | letter code | буквенный код |
| telecom. | letter code | алфавитный код |
| tech. | letter code | код буквы |
| gen. | letter-coded file | литерное дело (A registry file in KGB intelligence agencies containing materials relating to counter-intelligence work, or to diplomatic, trade and other missions and Soviet establishments abroad, or scientific and other delegations traveling abroad (from  google.com Tanya Gesse) |