Translation of "palochka" into Finnish

A letter added to the Cyrillic alphabet when used in writing several of the Caucasian languages. It looks exactly like uppercase Roman letter I, but has no lowercase form. In the days of the mechanical typewriter, this letter was the Roman numeral I, which was included on most Cyrillic typewriters for use in typing dates (e.g., 25.XII.1953 г.). [..]