wildcard ptr rec

[Marty Viilma <VIILMA @ Darwin . CMH . McMaster . CA>]

I've been trying to implement the strategy of returning an unknown.mydomain
response with a wildcard ptr rec but when testing the address to name
translation with nslookup it only return an A rec not found response.
The record looks like this currently:
*	IN PTR unknown.mydomain.

Do I need an A rec of some description as well?

Any help would be appreciated.

Marty