Can I have a *.domain.com A record

[ram]

On Mon, 2009-10-26 at 11:39 +0100, Stephane Bortzmeyer wrote:
> On Mon, Oct 26, 2009 at 04:01:31PM +0530,
>  ram <ram at netcore.co.in> wrote 
>  a message of 10 lines which said:
> 
> > Is it possible to have a A record for *.domain.com
> 
> Technically, yes. It is a very bad idea, but it works.
> 



Can you elobarate on that please. If  wildcard DNS is a bad idea, then I
need to tell my clients why ? 


Thanks
Ram