The nullfs mounts required in a FreshPorts ingress jail

mounts

I was wondering how to effeciently do all these mounts for a simple jail.

I found a reference here: https://forums.freebsd.org/threads/mount-nullfs-in-a-jail.72715/
"Still, the fstab.jail (see mount.fstab inside /etc/jail.conf) is best way to resolve this"

And another here: https://forums.freebsd.org/threads/using-nullfs-in-etc-fstab.59061/
"Don't add it to /etc/fstab if it's specific for this jail. Make use of /etc/fstab.<jailname> to mount 
it "on-the-fly" when the jail starts."

So why is this not documented in man jail.conf?

Then I found: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=244569
"please document path for mount.fstab in jail.conf(5)

#
# For the FreshPorts chroot within this jail
#
/jails/ingress01/root/bin             /jails/ingress01/root/var/db/freshports/ports-jail/bin           nullfs  ro,nosuid         0   0
none                                  /jails/ingress01/root/var/db/freshports/ports-jail/dev           devfs   rw                0   0
/jails/ingress01/root/lib             /jails/ingress01/root/var/db/freshports/ports-jail/lib           nullfs  ro,nosuid         0   0
/jails/ingress01/root/libexec         /jails/ingress01/root/var/db/freshports/ports-jail/libexec       nullfs  ro,nosuid         0   0
/jails/ingress01/root/sbin            /jails/ingress01/root/var/db/freshports/ports-jail/sbin          nullfs  ro,nosuid         0   0
/jails/ingress01/root/usr/share/mk    /jails/ingress01/root/var/db/freshports/ports-jail/usr/share/mk  nullfs  ro,nosuid,noexec  0   0
/jails/ingress01/root/usr/sbin        /jails/ingress01/root/var/db/freshports/ports-jail/usr/sbin      nullfs  ro,nosuid         0   0
/jails/ingress01/root/usr/bin         /jails/ingress01/root/var/db/freshports/ports-jail/usr/bin       nullfs  ro,nosuid         0   0
/jails/ingress01/root/usr/lib         /jails/ingress01/root/var/db/freshports/ports-jail/usr/lib       nullfs  ro,nosuid         0   0
/jails/ingress01/root/usr/libexec     /jails/ingress01/root/var/db/freshports/ports-jail/usr/libexec   nullfs  ro,nosuid         0   0