# Vertical tab is not a separator.
#
# POSIX specifies that <blank> is the serarator 
# in the POSIX locale, and <blank> is defined
# as <SPC> or <TAB>.    
#
# On the other hand, <space> includes Form Feed and 
# Vertical Tab.  By default, those should not be
# separators.
xargs_start p {printf "\[%s\]\n"} verticaltabs.xi