I'm surprised it wasn't mentioned, but they were also used for text entry in some text editing applications. For example, one could type ë by entering ¨ then f

I'm surprised it wasn't mentioned, but they were also used for text entry in some text editing applications. For example, one could type ë by entering ¨ then following with e. The ¨ would be displayed at the position where the combined character would be, while waiting for the second character to be entered. Once the second character is entered, the display would be updated with the correct combined character.