Partition naming, fstab, and geli

[David Allen]

Say I have performed a standard installation of FreeBSD onto a single IDE
drive with the following entries in /etc/fstab:

    /dev/ad0s1b  none  swap  sw  0  0
    /dev/ad0s1a  /     ufs   rw  1  1
    /dev/ad0s1d  /var  ufs   rw  2  2
    /dev/ad0s1e  /tmp  ufs   rw  2  2
    /dev/ad0s1f  /usr  ufs   rw  2  2

Then I added more drives.

1. The Handbook suggests there is a convention that when partitioning a a
drive that's been added, to label the first new partition on that drive as
'e' as opposed to 'a' (which is reserved for the /root partition).  Does
the following satisfy that convention, or would starting with 'a' in each
case make more sense?

    /dev/ad1e  /foo1  ufs  rw  2  2
    /dev/ad1f  /bar1  ufs  rw  2  2
    /dev/ad1g  /baz1  ufs  rw  2  2

    /dev/ad2e  /foo2  ufs  rw  2  2
    /dev/ad2f  /bar2  ufs  rw  2  2

    /dev/ad3e  /foo3  ufs  rw  2  2
    /dev/ad3f  /bar3  ufs  rw  2  2

2.  My second question is in regards to using the 'xx' fstype to have the
system ignore that device.

Consider, for example, a geli encrypted partition.  The .eli device
doesn't exist at boot time.  I discovered by accident that the system
won't boot with an fstab entry for a device that doesn't exist.  So if I
was to record an entry in fstab, I couldn't use

    /dev/ad1e.eli  /home/david/private  ufs  rw  0  0

Does that mean that the following is what's typically to record fstab
entries for ignored devices?

    /dev/ad1e.eli  /home/david/private  xx   rw  0  0
    /dev/ad3e      /fake                xx   rw  0  0
    /dev/ad3f      /reserved            xx   rw  0  0

Thanks.