Comment 3 for bug 913857

man ntp-wait also lists the '-f' flag, which is not a real flag (same source package I believe.) Let me know if you want a separate bug for it.
antarus@host$ man ntp-wait
NTPQ(8) NTPQ(8)

NAME
       ntp-wait - wait for NTP server to synchronize

SYNOPSIS
       ntp-wait [ -f ] [ -n tries ] [ -s sleep ] [ -v ]

DESCRIPTION
       ntp-wait waits until the locally running ntpd is in state 4 (synchronized). This could be useful at boot time, to delay the boot
       sequence until after "ntpd -g" has set the time.

OPTIONS
       -f Force hard failure if state is unknown.
< I omitted the rest ..>

antarus@host$ ntp-wait -f -n 100 -s 3 -v
Unknown option: f
Waiting for ntpd to synchronize... OK!