start of authority shortcut??

[Daniel Frazier]

I have two production SCO servers that I set up bind version 8.1.1 on a
while ago.  I was only using dns for internal name resolution, so I
kinda breezed thru setting it up and didn't really take the time to try
to really learn it.  One of the things that I included was a named.soa
file,
and at the top of each of the other relevant files I just put... 

$INCLUDE named.soa

Finally my company is bringing its web and email servers in house, and I
set up a master dns server on our firewall and made the two SCO boxes
slaves.  I bought the O'Reilly book DNS and Bind and took the time to
figure everything out.  Nowhere in any example I could find was there
mention of this soa shortcut.  Is it valid?  Is it safe?

Daniel Frazier