"x.x.x.x Subnet" not "x.in-addr.arpa"

Using 2003 AD integrated DNS; We added another name server to the AD
"domain"

We 1st ran dcpromo, then installed AD integrated DNS. The forward zones look
fine.

However we noted the reverse zone(s) before the addition had zones in a
naming convention
x.in-addr.arpa.

After the addition of the name server, it seems the way we defined the
reverse lookup zone on the new name server unintentionally as "x.x.x.x
Subnet"

This reverse lookup zone propagated throughout the entire domain AD DNS.
Looking at the contents of the x.x.x.x Subnet reverse zone, all the records
look fine.

Manually deleting/recreating or attempting to make new reverse zones result
in the "x.x.x.x Subnet" not "x.in-addr.arpa"

2 questions:

Is it critical the naming of the existing or any future created reverse
zones have the naming convention "x.in-addr.arpa"?

Is there a functional difference between the reverse zones named as
"x.x.x.x Subnet" not "x.in-addr.arpa"

Any advice or suggestions would be great.
Please reply to the group
Thank You,
Mike Bonvie