[root@adc:Standby:In Sync] config # tmsh save /sys ucs /var/tmp/foo.ucs
Saving active configuration...
/var/tmp/foo.ucs is saved.
[root@adc:Standby:In Sync] config # tmsh save /sys ucs /var/tmp/foo.ucs > /dev/null
Saving active configuration...
[root@adc:Standby:In Sync] config # tmsh save /sys ucs /var/tmp/foo.ucs 2> /dev/null
/var/tmp/foo.ucs is saved.
[root@adc:Standby:In Sync] config #

Seems F5 is not alone with such glorious ideas. A coworker pointed out that the "ipspace list" command on our old NetApps outputs a space and a backspace in some places.