I'm not sure what that's about, I have advanced access and can't reach it either so it must be a broken link. For the record, the picking of standard mortice locks isn't advanced... and that includes curtained locks as far as I know, it's the exact same principle just with different tools. The only restricted stuff in terms of mortice locks would be to do with bypass, decoders, pin and cam systems and so on. Picking double bitted stuff is probably a no-no though.
