["... at pckbd?", "... at scsi?"]

>I'd say it's bad style, at least.  (It is confusing.) ...
>I'm not sure it's right to disallow them; i mean, they _could_ be
>useful for some kernel configs.

Indeed, if I had wanted to disallow them entirely, the code for
"config" would be somewhat shorter.

Attributes serve two purposes.  One is to pull in service subroutines
(if_ether.c, subr_disk.c, etc.); the other is specifically so that
you *can* write "at scsi?".

The latter should be used only for "well known" attributes, like
when you go into the store and say "I want SCSI".  That way, even
though it is confusing, it is also "natural".

>They don't really have unit numbers, either, so what does 'scsi0'
>or something similar mean?

Actually, the definition is kind of sleazy: `scsi0' means `all
controllers with a "scsi" interface attribute and unit 0'.  I was
a bit tempted to require the unit to be `?' here...

Chris