The group's admin, through the group's ghost management features in the webapp, can link the ghost to a player they have already played with or to an email address. If the ghost is linked to an email address, it becomes a 'pending' regular user. If the invited player does not already have a user on rankade, they will receive an email inviting them to finalize the registration. If the invited player does not finalize their user within 15 days, the 'pending' user reverts to a ghost again.
Ghosts from different groups cannot be linked to the same email address until that user's invite has been finalized. After finalizing the first invite, other ghosts can be linked to the user and are converted automatically.
A ghost cannot be linked to the email address of another user within the same group. However, it can be linked to the email address of an existing rankade user who is not yet part of that group.