I think the rules technically exclude the arXiv as a qualifying outlet. Without limiting any other provision in this Section, a publication lacking any of the

I think the rules technically exclude the arXiv as a qualifying outlet. Without limiting any other provision in this Section, a publication lacking any of the following characteristics will be deemed not to be a Qualifying Outlet: i. an editorial board whose members are named and available for contact; ii. an editor or editorial board member whose professional knowledge of the global mathematics community would enable him or her to identify an appropriate referee to review a submitted paper; iii. a published refereeing process that, in the opinion of CMI, ensures that a submitted paper is reviewed and verified by appropriate experts in the field of the Problem; or iv. inclusion in the list of publications maintained by MathSciNet. The solution to the Poincaré conjecture was only accepted after an exposition of Perelman's proof was published in a refereed journal. His papers didn't qualify, but of course he got the credit for the result.