can @ be CNAME?

[Tech W.]

--- On Tue, 23/11/10, Matus UHLAR - fantomas <uhlar at fantomas.sk> wrote:

> From: Matus UHLAR - fantomas <uhlar at fantomas.sk>
> Subject: Re: can @ be  CNAME?
> To: bind-users at lists.isc.org
> Received: Tuesday, 23 November, 2010, 3:58 PM
> On 23.11.10 15:50, Tech W. wrote:
> > can I set @ to a cname type? like:
> > 
> > @  IN  CNAME  www.example.com.
> 
> Certainly not. for a domain you have you need SOA and NS
> records, and CNAME
> is incompatible with both of them.
> 

But why @ can have an A RR?

@ IN A 12.34.56.78

This seems OK for us.