The file with a strange name in this directory is no mistake.
It shows that Linux handles filenames in Unicode (UTF-8)
without ever realizing that they are in Unicode.
[However, some old tar's are unhappy with this filename.]

If you want to see it (the filename consists of two musical notes):
% consolechars --default-font	# load PC font, just to be sure
% echo -e '\033%8'	# set Unicode output mode
% ls -N			# show filenames (raw)
% echo -e '\033%@'	# set Latin1 output mode again.

If you want to remove it:
% rm ./??????

If you want to input Unicode:
% kbd_mode -u		# Be careful! Do this only with a kbd_mode
			# from kbd-0.88.tar.gz or later!
and next tell loadkeys what key combinations correspond to which
Unicode values. (See also the contents of that musical file.)

See also the scripts unicode_start and unicode_stop in ../src.
