I´m searching for an addon which allows users not only to bookmark a thread, but also a whole subcategory. Thank you for your help!
There's a permission in the roles section called AdvancedNotifications. If you are admin, you can see what it does if you look at your own notification settings.
But I've heard it said that those notifications do not scale very well. So you might want to allow them only for a few users at first and maybe never for all of your users...
Thank you very much!