lame delegations

> ISP-A needs the ability to say "Attention $REGISTRAR, $HOSTNAME is no 
> longer valid, as evidenced by the current lack of a PTR record. 
> Please remove it".

Indeed. Insist on a true NXDOMAIN response to authorize removing of
the record, so that records cannot be removed due to nameservers having
technical problems.

> Of course, this is a great idea, but can we actually get it 
> implemented by the relevant agencies? ;-)

I think it has the best chance, because at least it does not require
coordination between agencies!

-Phil