About reverse DNS

[lrider]

Hello,

I have 2 questions about how the reverse zones are generated by ispconfig:

1) What triggers the generation of a new zone?
2) What triggers the inclusion of a record in the reverse zone?

The thing is that I have 5 reverse zones in my server when I only have 1 range of Ip's.

Also I don't understand what takes for a domain to be included with a ptr record in the reverse zone.

Thank's in advance.....Larry.