
\S terminal mode: standout mode: reverse video \S

Terminal mode refers to the way your terminal prints characters.  Normally,
it prints all characters the same way.  You can make certain characters or
entire words stand out from the rest of the characters by marking them with
a backslash character "\" followed by an "S".  The characters marked this 
way will print in standout mode.  Paper printing terminals and some video 
display terminals like the Hewlett- Packard 2621, show standout mode by 
underlining the characters.  Other video display terminals like the 
Hewlett-Packard 2640 terminal swap the background and character colors.  
This form of standout mode is called reverse video.

