Hey Javier... Finally someone who answers...

What you mention is "fine", but being a Mod, you´ll probably be aware that the system keeps track of who is the Referral team, etc. If you share IP with that Referral, then that is ilegal, per FAQ #22 & 23. Technically, that account should be blocked.
Some people are not aware that someone has listed them as a Referral, someone who shares IP with them, such as a family member, schoolmate, coworker, etc. One day, they find their account blocked. Just because, one day, that person mentioned they play a game called 11x11, or someone who uses the same computer, saw that game in the pc history.
What I am getting at, is that with a private link, it is 100% sure that the person who is listed as a Referral, is 100% responsable for it. That if their account is blocked, it falls 100% on their shoulders.
Right now, accounts are blocked and they could have been prevented.
I´m a very active Mod in the Spain server.

I´ve also been a Mod (and Head-Mod) in other large games, such as Pcliga.com. Where in every game, there were only "private links for Referral".
Anyways.... I won´t lose hope that this gets changed... listing a Referral has a bonus to it. Someone won´t stop registering if they can´t list who Referred them. hehe
Take care! Hopefully, someone with higher powers, will reply. But my hope is quite low. -.-