> 	Furthermore, setting a variable with that value first, and using it as the
> arg to set works fine.
> # var='root:foo:bar:bax'
> # set $var
> # echo $1
> root
> 
> I have no idea whether it's supposed to work like that or not.  It certainly
> seems non-intuitive.

SUSv3 says Field Splitting happens after a) parameter expansion, b)
command substition, and c) arithmetic expansion.

After learning this fact it's pretty clear to me how things work. :-)

Masao