Puts the Editor into insert mode, allowing you to enter literal keystrokes into your file, even if the keys are bound to commands.
For example, suppose you customized the Editor so that every time you press d, the cursor moves down one line. This makes it impossible to type the letter d in the file. When you turn on insert mode and press d, the letter d appears in the file, and the cursor does not move down one line.
Insert mode may be turned off by the FlashCursor command (see FlashCursor).