reverse domain delegation

[Robert Moskowitz]

Well I and my ISP have finally gotten my IP addresses delegated to me.

I am running the zone:

192-26.78.84.65.in-addr.arpa  and I want to setup a secondary across country.

My colleage back in the labs is all ready for that, but is it enough that I 
put an NS record for his server in my zone file, or do I also have to get 
my ISP to put it in the parent zone?