Is there a global switch anywhere, I know how to do it for ordinary forums, but I would like to be able to do it at the main start page? 
I can’t see one to mark the whole form as read in one hit. Unless its hidden or turned off still !! However you can mark an individual forum as read by going in to it and using the “more options” button at the bottom of the forum. This then brings up a “mark all read” button amongst various other filter options.
Not being able to mark everything read in one hit may be a disadvantage but with this forum all posts remain unread if indeed you have not read them when you log in and out, unlike most others where stuff will get marked as read if you log in and out whether you have looked at it or not. Meaning you either miss stuff ir you have to read everything new in one go! Combine that feature with the “posts you have not read” link which you can then filter according to various options such as “new since last visit” and I think keeping tabs on everything on here is quite an easy task. I have been clicking straight on the “posts you have not read” link on most visits.
Was going to ask the same question…
Sometimes I cant get on the forum for a week or two, this may mean an awful lot of new posts…
Woud be nice to be able to mark all red after I have picked out the ones I want to read [;)]
When you use the view posts unread link you can filter the results to new, 1 day old 2 days old etc… not the answer but a work around whilst we find the mark all read button, which only seems to feature in individual forums at the moment.
Have seen said button on another CS car forum so it can be done…