Separating data into multiple files
The $INCLUDE line allows data for a given zone to be separated
into multiple files. For example, mailbox data might be kept separate
from host data by including this line in a resource record:
$INCLUDE /usr/named/data/mailboxesThe line is interpreted as a request to load the file /usr/named/data/mailboxes.
Additionally, you may append a temporary $ORIGIN to use while the file is read. For example:
$INCLUDE /usr/named/data/mail-exchangers $ORIGIN mynet.COMThe inclusion of the new origin will not cause data to branch into another zone. Only the boot file can introduce or redefine zone boundaries.