Whoooo Hoooo! I just figured out the answer to this question!
For anyone else wanting to bookmark a subject - When reading the topic go to the top of the topic page to the gray box that says "Thread Tools". When you click the little down arrow next to it you get three options. One of them is "Subscribe to this thread" Select that option and it will give you the choice to subscribe to the tread with notification or bookmark the page. Whoooo Hoooo! Ann in TN