I have to say that I don't look at marks or manuals much. I just put in a new needle and remove anything in the way from seeing the tip of the hook. Turning through to see the tip of the hook in relation to the eye of the needle. Funny how some old manuals even talk about fudging the needle position with certain fabrics and thread types. This is not news to you I'm sure, but new floks may not have seen it.