404. That’s an error.
The requested URL /add?feedurl=http%3A//www.lavoro.org/rss/Architettura_Edilizia_Design/rss_cat8.xml was not found on this server. That’s all we know.
/add?feedurl=http%3A//www.lavoro.org/rss/Architettura_Edilizia_Design/rss_cat8.xml