404. That’s an error.

The requested URL /add?feedurl=%3Ca%20href%3D%22http%3A//feedvalidator.org/check.cgi%3Furl%3Dhttp%253A//glutenagogo.blogspot.com/feeds/posts/default%22%3E%3Cimg%20src%3D%22valid-atom.png%22%20alt%3D%22%5BValid%20Atom%201.0%5D%22%20title%3D%22Validate%20my%20Atom%201.0%20feed%22%20/%3E%3C/a%3E was not found on this server. That’s all we know.