Some of Cloudflare's optional features, including Rocket Loader and Email Obfuscation, use non standard tags that will never validate if you are checking the code through something like w3.org. As these services are more strict than a web browser, this does not mean your site visitors would be having issues because of the markup errors.
Not finding what you need?
95% of questions can be answered using the search tool. This is the quickest way to get a response.