10. The tie points down, whereas on the 11 it points horizontally outwards. You remember that big blue book that smells nice, that you don't use very often...........? Thank you Rob! It's funny you should say that, we're house sitting at the moment, so I only brought a reduced library with me: Spink, CCGB, British Coins market values - just the ones I use for valuations. That was so I could fit the whole shooting match in a tuck box. So far I've wished I'd brought Davies, ESC, both Grooms, and now Peck. I have a little pile of coins that can't go further in the system till I get to use those references, and that was one of them!