[Help-gnu-radius] Configure User-Name format?

[Greg G]

I'm looking to update my radius server, and I've hit a small snag with 
GnuRadius 1.1.  It doesn't like one of the usernames that I have in my 
users file.  This user happens to have an ampersand in it.  As far as I 
can tell, RFC 2138 allows for this in the User-Name field if the format 
type is "simple."  It looks like GR is using the "monolithic" format as 
default.  Is there a way I can override this setting?

Thanks.

-Greg G