ntpd with flags in rc.conf

[Zbigniew Szalbot]

Hello,

I read this in the handbook:

To ensure the NTP server is started at boot time, add the line 
ntpd_enable="YES" to /etc/rc.conf. If you wish to pass additional flags to 
ntpd(8), edit the ntpd_flags parameter in /etc/rc.conf.

Now, I understand that the additional flag may be for example pid 
(-p /var/run/ntpd.pid).

So how do I put that flag in /etc/rc.conf where I have ntpd_enable="Yes"?

Many thanks for your advice!

--
Zbigniew Szalbot