I'm perfectly aware that the server doesn't track the actual messages, but earlier discussions about this topic somehow implied that it track the time when I start reading (eg when I click into the Poser board) and then marks that - this is a big difference. Let's say I enter the board at 10am and read slowly to the final page until 11am. If I hit mark-all-read, will it hide everything older than 10am, or everything older than 11am? Earlier answers implied 10am, but now I'm afraid it is rather 11am.