Subscribe to a Thread
To Subscribe To a Thread first click on the thread. Next scroll down to the very bottom of the thread and click on the teeny words “Subscribe to this thread” at the bottom left of the page directly above the words “User(s) browsing this thread:”
OR
Look for the words "Subscribe to this thread." just above the thread on the left. (Exactly where they are will depend on which template you are using to view the forum.)

A new page will appear with options for subscribing.
Choose to subscribe without notifications, with email notifications, or with PM notifications. If you turn on notifications, we cannot turn them off for you. You will have to do that yourself through UserCP.

If you subscribe without notifications, you can view the list of your subscribed threads in your UserCP.
You are now subscribed to this thread.