What does the "Mark All Read" button do in forums ?

If you've been away from the HBC site for a bit or just want to keep up with current forum discussion without having to read older entries, the "Mark All Read" button is a quick way to catch up. If you're viewing a specific forum such as "The Pink Room", only the topics in that forum will be marked read. If you're viewing the list of All Forums, this button will mark all topics in all forums as read.