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".