Why do I need to be able to get another person's GUID? If it is required for future hacker reporting or kicking/banning by playeradmins and the name isn't reliable enough for keeping track of who is who at any given time, then why can't the server just generate a sort of session ID that it ties to the GUID? It could send it to other players if needed and keep the GUID secret. The ID could be generated from a hash of PlayerGUID+SomethingSecret+SomethingThatChanges(like server join time) or something like that.