404. That’s an error.

The requested URL /catalog/product_compare/add/product/2743/uenc/aHR0cDovL3d3dy5sZW9uc2FmZXR5cHJvZHVjdHMuY29tLzItcGllY2UtcGxhc21hLXRocm93aW5nLWtuaWZlLmh0bWw,/form_key/NHR8HFAPkjBtaqyI/ was not found on this server. That’s all we know.