I've looked but I haven't found the actual coding to do this.

I'd like people to automatically be subscribed to a main forum so that everyone gets system announcements and such. This would be easier then the group e-mail option. I see the template, user_profile_email.html, and I'm thinking I could just insert a hidden input line in there. However, what happens when people go there and the main forum is displayed along with the rest of the forums? What happens if they check or upcheck this? Surely someone has been down this road.