404. That’s an error.

The requested URL /catalog/product_compare/add/product/483/uenc/aHR0cDovL2NsZWFudHVuaW5nLmNvbS9ibXcteDUtMDAtMDMtZmxhdC1ibGFjay1mcm9udC1raWRuZXktZ3JpbGxlLWN0LWJtd3g1NTM0Lmh0bWw,/ was not found on this server. That’s all we know.