SET(PAD_OVERSTRUCK_TABS)

     Determines what TPU does when a user, working in a buffer whose text
     insertion mode is OVERSTRIKE, types one or more characters in the white
     space created by a tab.

  Syntax

     SET (PAD_OVERSTRUCK_TABS, {ON | OFF}

  Parameters

     ON                   In a buffer where the text insertion mode is
                          OVERSTRIKE, ON causes TPU to preserve the
                          column positions of existing text when a user
                          enters text in the white space created by a tab.

     OFF                  In a buffer where the text insertion mode is
                          OVERSTRIKE, causes TPU to convert from tabbed
                          space to blanks any white space to the left of the
                          inserted text, remove the tab, and replace it with
                          inserted text.  As a result, text to the right of
                          the tab often moves left when the tab is removed.