eric_
You're right, this name exists and has been adopted by the CEC: http://www.edinburgh.gov.uk/directory_record/842497/bishops_walk
So I added it, even if I don't remember any plaque to mention this name there. I added "access=private", "foot=yes" and "bicycle=yes" to the road as it's its current use. "bicycle=permissive" could maybe be used here.