404. That’s an error.

The requested URL /bookmarks/mark?op=edit&bkmk=https%3A%2F%2Fdata.bnf.fr%2Fen%2F16568661%2Fnikolaj_vasil_evic_krivenko%2F&title=Nikolaj+Vasil%CA%B9evi%C4%8D+Krivenko was not found on this server. That’s all we know.