Custom message for authentication

Hi,

we are running INN with Perl filter for authentication. We do not 
require the authentification for the 'trusted' hosts, e.g. the ones, can 
be tracked to a trusted local ISP.

For now, if a username/password is not set by a client, the server 
resonds with 480 response, and it seems the response is not comming from 
the Perl auth filter.

Is there any way to customize this response, the way 481 response can be 
customized by the return values?

-- 
ejs