From Tibia.com News Archive
"From today on, there is a new option called "Bring Back a Buddy" on your account page which allows you to invite back retired friends who have left Tibia. You can find it on the same page as the "Invite a Friend" option. All you need to do is enter a character name in the designated box there and we will send an email to your friend's address to let him know that you are waiting for him in Tibia.
If your friend logs into the game afterwards, we have a small surprise for him to help him start off again: 10,000 gold coins for each year he did not play will be delivered to the home depot of the first character he logs in with.
In addition, if your friend decides to buy new premium time within 90 days after your invitation, you will get some bonus premium time yourself! You can only invite players who have not logged into the game or on the official website for a minimum period of one year. Please also note that you can only send an invitation to a retired friend if he was not already invited by someone else before."