I would like to suggest to add a "Mark all topics in this forum as read" button. Because I noticed that even if I visit a forum, after different visits all the topic not read stay as "not read".
The problem comes when the forum has a lot of activity. For example the english support forum has plenty of new topics every day, and I can't open all of them to mark them as read. So there is only one solution:
- Going to the forum from desktop and click on mark as read