Continuing the discussion from The Society's Community "How To" Guides:
Some threads can generate many replies over a long time. In other forums it can be hard to follow these threads as new replies appear and you have to find what might be new to you and what you have already read.
In this community, the site will keep track of what comments you have already read, and when you next visit that thread you will automatically be taken to the point where you stopped reading.
In addition, there is a slider on the right of the conversation thread that shows you your progress through the comments. These are numbered for ease of reference. It will show you how many posts there are in total and what post you were on. You can also use this slider to move back and forward through the conversation if you wish.