        ou -- Option Unprintable

               default range             syntax
                 1,$                     ou[character]

        The  "u"  option  is  for  monitoring  unprintable characters.
        Typing "ou" by itself will return the current  character  used
        to display unprintable characters.  If it is ' ' (blank), then
        unprintable  characters  are  not  checked and may mess up the
        display.  Typing "oux" where "x" is a printable character will
        turn on  character  checking  and  display  "x"  everytime  an
        unprintable  character is encountered.  Unprintable characters
        are not disturbed in the file, but can be "edited" out.

        See also hccmisc for refreshing the display.

        For general information about the option command, type "ho".
