Must /tmp be on boot partition?

["Marc Sherman" <msherman@myrealbox.com>]

Does /tmp have to be physically located on the boot
partition, or can it be a symlink to /var/tmp on another
partition?  I've seen conflicting statements in different
references/howtos/manpages - some say that the link works,
and others say that the boot process needs temp space, and
uses /tmp for that purpose, so it needs to be on the boot
partition.  Does anyone have conclusive proof (ie: a working
system of their own) that the symlink to /var/tmp works?

Thanks,
- Marc