Mark as read button

Hi,
do I look over it? Or is it simply not here? A mark as read button is what I'm looking for.
The forum show me more then 400 unread posts (wich is true) but these posts are so far back in history I'm not really interested. Is it possible to mark them as read?

Edit: someone found it but it gave an error. I can't see it, am I blind? Or has there been a change since 2012?
Edit 2: just click the arrow... Sometimes I'm hopeless. Let's blame the operation.

[Like Ra]

just click the arrow

Yes 😉 Unfortunately does not work for sub-forums (e.g. the shopping ones). So you have to explicitly click on the sub-forum arrows.