Alphabetic shift
Provided by the ASK Keyboard Dictionary
Aka/also known as: alpha shift, lower shift
Alphabetic shift was a key on IBM data entry (DE) terminal keyboards used as an override to allow the user to enter alphabetic characters into a numeric input field or when the host terminal is in numeric mode. As alphabetic characters were printed at the bottom of a keycap's face, the alphabetic shift is also known as "lower shift". When present, the alphabetic shift took the place of the right shift key and was represented by an upside-down shift arrow symbol.
