[lug] problem creating a boot-CD-image

distri SuSE 9.2 prof
I did all jobs (written in the administrators manual);
files in
/tmp/iso/boot/grub/: stage2_eltorito
/tmp/iso/boot/: message, vmlinuz, initrd, menu.lst
then at /tmp>#
mkisofs -R -b boot/grub/stage2 eltorito -no-emul-boot -boot-load-size 4
-boot-info-table -o grub.iso iso
The problem is the following message:
"Info: UTF-8 character encoding
detected by locale settings.
Assuming UTF-8 encoded filenames on source filesystem,
use -input-charset to override."
Sorry, I'm not a specialist. "use -input-charset to override" - what must I
do?

Thanks for help.