Make aliases that don't transfer?

[Jeff Lightner]

We have multiple domains that are aliased to our main domain.   This
works fine.
I've noticed on doing zone updates and transfers from master to slave
that it essentially transfers the alias zone file for EACH aliased
domain.   This seems unnecessary since the zone file is a single one for
all these domains so it seems the transfer for the first alias should be
sufficient.   I was curious how I would insure it only transferred once.
Is there a type other than "master" or "slave" or should I just take out
the "allow transfer" line?   I don't want to delete the entry entirely
from the slave for obvious reasons.

Example from my master:
zone "4waters.com" {
        type master;
        file "watercom-aliases";
        allow-transfer { watercom; };
};