I know I can block members, but don't want to block them if they only started a thread that doesn't interest me. I looked for the user guide in this forum, but couldn't find it either. But, don't know if this is even in the User Guide.
There are a couple threads here that I never read that get bumped a lot. I just click them and hurry and swipe back to the new posts list. I do this because I don't like to have any new posts showing after I visit. Another option is to select "Mark Forums Read." This will clear everything from the new posts list so you don't have to click on threads you aren't interested in.