Click on the "W3C" button (XHTML Validator).
The following error:
Status: 403 ForbiddenVary: RefererContent-type: text/html
The W3C Validator Team
Sorry! This document can not be checked.
No User-Agent header found!
Please identify your software properly by providing the HTTP User-Agent string. Default from an underlying library (eg Java, Ruby, Coda, libwww) is not sufficiently unique in identifying your software. A good practice is to include a URI to more information about your service or software.
You can check it also in the demo Rad Editor:
It looks like the request format has been changed on the http://validator.w3.org/ side.
Could you please help me to resolve this problem?
Thank you in advance.