Syntax: Insert [0|1]
Abbreviation: I
sets the insert flag. If this flag is true, the text you type is
inserted, otherwise it overwrites the existing characters. This also
governs the behaviour of the InsertChar and InsertString
commands.
If you invoke Insert with no arguments, it will toggle the flag. If you
specify 0 or 1, the flag will be set to false or true, respectively. A lower
case ‘i’ will appear on the status bar if the flag is true.