How to hide databases?

Hello! We are using Informix and everybody gets a list of all databases if he takes a look with dbaccess->select->databases. There are some databases which are only for a few guys supporting a different produkt. Is it possible to 'hide' databases that someone doesn't need to know about? I read about dbspaces but I found nothing about what happens if I use different dbspaces. I found a way by starting Informix with a different SERVERNUM, but the machine (SUN-Ultra-Sparc) is very slow after starting the second set of oninit procs. Thankx, Erik