for the disklabel: This facility is OBE.
First of all, we cannot sensibly implement this in a properly stacked
environment.
Second, if we did, it would confuse the heck out of users who
wouldn't be able to "start from scratch" by dd(8)'ing /dev/zero
onto /dev/da0.
Third, the offered protection is not comprehensive: no other software
would respect it.
Fourth and finally, the disklabel is already protected against
tampering if it controls open partitions.
Uselessness of these options discussed with: peter
f080d33b66