Why is stealth secondary queried for address of primary?

[Super-User]

In article <200006152123.HAA04977 at bsdi.dv.isc.org>,
	Mark.Andrews at nominum.com writes:
> 
>> At 07:12 PM 06/15/00 +1000, Mark.Andrews at nominum.com wrote:
>> >
>> >	Well nameservers send out the current set of nameservers for the
>> >	zone as found in the zone.  If you want a server to be a stealh
>> >	server don't=A0list it in the zone or the parent zone.
>> 
>> Yes, I understand that.  I used the wrong term -- I said stealth only
>> because it it's not listed in the root servers.  I just haven't updated my
>> domain record yet.

Could you explain that? For a stealth server, is it sufficient to put a
"notify no" in each zone stanza?  what does "don't=A0list it in the zone"
mean?

Thanks