allow-query for a zone

[Jeff Peng]

> Whether you set allow-query to none, or remove the zone statement,
> clients will get an error when they try to query the zone.

There is a difference when you develop a web interface for DNS system.
A user can "pause" the domain from web interface, if we remove the zone 
and records from BIND files, how will we do if user choose to enable the 
domain?
But with allow-query none, only adding a statement we can "pause" the 
domain for querying, but can re-enable it by removing this statement later.

Thanks.