I just signed up for SEOMoz and sent my site through the first crawl. I use the tilde in my rewritten URLs. This threw my entire site into the Notice section 301 (permanent redirect) since each page redirects to the exact URL with the ~, not the %7e. I find conflicting information on the web - you can use the tilde in more recent coding guidelines where you couldn't in the old. It would be a huge thing to change every page in my site to use an underscore instead of a tilde int he URL. If Google is like SEOMoz and is 301 redirecting every page on the site, then I'll do it, but is it just an SEOMoz thing? I ran my site through Firebug and and all my pages show the 200 response header, not the 301 redirect. Thanks for any help you can provide.