OVERSTRIKE MODE

 Sets the mode of the current buffer to overstrike, as opposed to insert.
 As you type, the new text replaces existing text at the current position
 ---hence, overstrike mode is sometimes called "replace mode" or "type-over
 mode."

 Usage notes:

 o  The mode of the buffer is shown in the status line.  It also affects
    some commands and keys such as DELETE, ERASE CHARACTER, and RESTORE
    CHARACTER.  For a list of these commands and keys, see help on CHANGE
    MODE.

 o  If you use SET BOX NOPAD, the mode of the buffer determines the effects
    of some box editing operations.  In overstrike mode, cutting a box, or
    erasing a box selection with pending delete, pads the area with spaces
    to keep the column alignment of text to the right of the box, and
    pasting or restoring a box overwrites existing text.  To override these
    effects, use BOX CUT INSERT and BOX PASTE INSERT.

 o  The Insert or Overstrike indicator on the status line is a toggle
    button---clicking MB1 on the indicator is the same as using CHANGE MODE
    (CTRL/A).  See help on Status Line.

 Related topics:

    Status Line     CHANGE MODE     INSERT MODE     SET BOX NOPAD