nameserver name

[Luis Silva]

Hi all,
I'm implementing my network and I'm facing a problem regarding the Name
Servers names. I noticed that is it possible to name the Name Server without
not considering the name of the zone. For example, for the "microsoft.com."
zone there is a nameserver named "ns1.msft.net.". For this case this name
server is also authoritive for "msft.net." zone. But, what happen if the
name server is only authoritive for the first zone? there is an example in
rfc 1034 where is occurs. The name server "c.isi.edu." is authoritive for
the  "." and "edu." zones but not for "isi.edu.". what happen if a client
contacts directly a name server from the "isi.edu." zone with the query "A"
"c.isi.edu.". This can happen right?
Can you clarify me on this issue. I would be very pleased.
Kind Regards and many thanks,
Luis Silva