On a disk with two different NetBSD installations, in two different
MBR partitions, (in my case i386 and amd64), what should the disklabel
partition "c" look like?  Does it even matter?  I can't find mention
in disklabel(5) or disklabel(8) of what disklabel "c" is used for.

Sysinst is setting "c" by default to be sectors from the second
installation's MBR partition, but that's not the only "NetBSD
partition" on the disk.

  Alan