Personal use is unrestricted. If the images are to be disseminated in any form (via website, print publication, or any other means), you must request permission for use via email to email@example.com. Permission for use in scholarly publications is routinely and quickly granted. Use of the images must be accompanied by the one-line notice "Image courtesy of the Clay Mathematics Institute". Commercial use will be granted on a case-by-case basis and after execution of a royalty agreement with CMI and the Bodleian Library.