URLs with irreversible IP numbers

Humor me and try the following URL:

        http://1.2.3.4/

The error returned by squid is that the host is not found.
Which is, of course, incorrect. Indeed, there is no reverse
mapping for this IP address, but that doesn't mean that it
should refuse to retrieve the page (maybe the host exists,
well, not in this case, but you get the point).

Any config-options I'm overlooking? Or is this simply a feature/bug?

-- 
Sincerely,                                                          srb@cuci.nl
           Stephen R. van den Berg (AKA BuGless).
"Well, if we're going to make a party of it, let's nibble Nobby's nuts!"