In NATO circles, the export versions, Mi-25 and Mi-35, are denoted with a letter suffix as "Hind D" and "Hind E". Soviet pilots called the Mi-24 the "flying tank" (летающий танк; "letayushchiy tank"), a term used historically with the famous World War II Soviet Il-2 "Shturmovik" armored ground attack aircraft. More common unofficial nicknames were "Galina" (or "Galya"), "Crocodile" (Крокодил; "Krokodil"), due to the helicopter's camouflage scheme, and "Drinking Glass" (Стакан; "Stakan"), because of the flat glass plates that surround earlier Mi-24 variants' cockpits.