Compose Key on Sun Keyboards
The Compose(key) on Sun Type 6/7 keyboards
allows you to type characters not available by ordinary key presses, such as Æ, ṅ, Ð, and so on.
In order to produce such characters, you first press Compose and two additional keys which compose the character, for instance:
Compose, ", a → ä
or
Compose, ,, c → ç