newbi question ... please help

[Oswaldo E. Aguirre M.]

Hi, I'm new in this list ... I've been looking in some places but
didnt got the answer ... I'm pretty sure this must have been in the
archives but they are too big .. my question is, how do I construct
reverse files for subnets of a class C network .. if anyone can
get me the answer of let me know where can I find the answer, I'd
pleased to look for it ... the thing is, we have many class C networks
and we have divided them among some institutions, say network 1.2.3.0,
institutions A, B, C, D ... is there a way to delegate subnet

1.2.3.0/26 to A
1.2.3.64/26 to B
1.2.3.128/26 to C
1.2.3.192/26 to D


what should I put in the 3.2.1.in-addr.arpa master file for this to work?

thanks in advance

-Oswaldo