Almost right. Super and Hyper are pure modifiers and can be combined with any key. On the original Space Cadet keyboard, Top and Front were used to type Greek

Almost right. Super and Hyper are pure modifiers and can be combined with any key. On the original Space Cadet keyboard, Top and Front were used to type Greek letters and symbols. (Not all of the symbols shown on the keys could actually be entered, however.) The later Symbolics keyboards had a Symbol key for this purpose.