404. That’s an error.

The requested URL /catalog/product_compare/add/product/1492/uenc/aHR0cDovL3d3dy5idXlpbmdmdXJuaXR1cmUuY28udWsvY2hpbGRyZW4tcy1mdXJuaXR1cmUvYnVuay1iZWRzLWZ1dG9uLWJ1bmstYmVkcz9wPTI,/form_key/p6MtLMN3QvxNM5mK/ was not found on this server. That’s all we know.