I have just been referred to this page when I asked the same question. You can see why users are confused;
Most of us are used to forum software which will inform us either immediately, or daily, whatever, according to our preferences set, for receiving emails, when we
subscribe to posts.
If you go to the "User Control Panel" -> "Overview" -> "Manage subscriptions" it will say
Below is a list of forums and topics you are subscribed to. You will be notified of new posts in either. To unsubscribe mark the forum or topic and then press the Unwatch marked button.
If you go to "User Control Panel" -> "Overview" -> "Manage bookmarks" it will say
You can bookmark topics for future reference. Select the checkbox for any bookmark you wish to delete, then press the Remove marked bookmarks button.
These two sections
clearly have separate functionality, and one should not be confused for the other.
I think the moderators need to address this issue either through re-education or correction, because on the Internet bookmarks do not fulfil the function of subscription to forum threads. They are bookmarks only, as is pretty clearly stated by this forum software. So if the subscription function is not working, could you please either upgrade the software or remove it in the Admin control panel, or have it fixed. This would save a lot of unnecessary confusion.
"When a Dzogchen Yogi hears Shakyamuni Buddha turning the Wheel of the Dharma of the Four Noble Truths he hears Samathabhadra proclaiming the most profound Dzogpachenpo." - Nyoshul Khen Rinpoche