Terminology

There has been frequent argument about whether this series of heavy tanks should correctly be termed the ‘IS’ or ‘JS’ series in English.  Joseph Vissarionovich Stalin’s name is written in the Cyrillic alphabet as Иосиф Сталин. The usual English transliteration of the Cyrillic letter ‘И’ is ‘I’, which leads to the transliteration of the complete name as ‘Iosif Stalin’ and therefore makes the abbreviation ‘IS’.

However, the letter ‘И’ is commonly though not necessarily consistently transliterated in German as ‘J’ in which case the name becomes ‘Josif Stalin’ and the abbreviation therefore becomes ‘JS’. Since the western Allies’ first information on these tanks came from captured German intelligence documents in 1945, in which the vehicles were designated ‘JS’, the series was known for many years to western analysts and historians as the JS series.

Throughout this site, I will use the term ‘IS’ throughout for  reasons of consistency.  Bear in mind that both ‘IS’ and ‘JS’ are arbitary designations, merely transliterations of the Cyrillic abbreviation ИC, so there is little point in arguing over such semantics.  Note that some kit manufacturers use the terms 'JS' and 'JSU' for their kits and when describing the names of those kits, I have used the kit manufacturers' designations.