Connection for Postgres from Designer

[David Goodenough]

OK, so I abandoned the Deb file for GNUe-Common, downloaded the tarball and
installed it.  Now Forms and Designer install and run properly.

Now I come to use Designer to set up a form.  I have read all the
docs that I could find both on the web site and on my machine but when I 
get to the bit asking for a connection definition nowhere could I find 
a definition of what I need.  I am not (yet) a python speaker so if this
is just a Python question I apologise.  I am trying to attach to a 
Postgresql DB on a Linux box, from a Linux box (initially the same one
but eventually over IP on a LAN).  

Whats the magic incantation?

Thanks in advance

David