Comment 8 for bug 1089767

> The data shows up in that field and can be seen in the patron summary
> page, but AFAIK, there's no actual functionality that uses it. (For
> example, and off the top of my head, no collection letters shall be sent
> to a juvenile, but to the parent/guardian)

There is an additional mechanism already present that could be a
starting point, namely patron groups. Patrons that are linked
together via actor.usr.usrgroup will have the total fine balance owed
by the group displayed in the staff client, and designating a patron
as a group lead is effectively asserting that they're financially
responsible for the group.

There isn't currently much more to the feature than that, but even its
current state, it gives us the ability to store patron/responsible
patron relationships between patrons, from which to build things like
group notices and (perhaps) the ability for group leads to see the
financial obligations occurred by other group members.