This is possibly a very stupid question, but I'll ask it anyway. I understand that the markings on a Rolex Crown indicate the level of sealing. What does a cross indicate - I can't find this information anywhere, and haven't seen a similar crown anywhere else? Photo uploading has defeataed me again, so I am putting in a link to Flikr, where I have stored a picture of the crown -

http://www.flickr.com/photos/34544538@N04/3230474641/

Thanks,

Andrew