Actually I think the question is clear enough; it's basically "here is a strange notation in my textbook and I can't figure out how it's supposed to work". If it looks inchoate its just because the asker dind't already know the answer.
Well, under normal circumstances it would be enough to click on the link marked MS in the message posted by Smokie. I am not sure why the linked website is down and how long it's been this way.