Reverse zone

[Rok Pergarec]

Hi,

I'm having problems with reverse zone. First of all, should I have a 
reverse zone like ip.in-addr.arpa if my network doesn't support reverse 
lookups for any reason?

so I have the


zone "my.ip.in-addr.arpa" in {
         type master;
         file "/var/named/pz/my.ip";
};

in my named.conf... my.ip file looks like this:


$TTL 1D

@               IN      SOA     my.domain. root.my.domain. (
                           2000106039    ; serial
                           8H            ; refresh, seconds
                           2H            ; retry, seconds
                           1W            ; expire, seconds
                           1D )          ; minimum, seco

                         NS              my.domain.
                         NS              my.sec.server.

1                       PTR             dns.my.domain.

Since I'm new to bind I don't really know how does this works... in 
other words.. in don't undrstand the PTR records...

Thanks in advance.
Rok