404. That’s an error.

The requested URL /bookmarks/mark?op=edit&bkmk=http%3A%2F%2Fdata.bnf.fr%2F13912912%2Fmichael_haydn_concertos__trompette__orchestre__re_majeur__mh_104%2F&title=Concertos.+Trompette%2C+orchestre.+R%C3%A9+majeur.+MH+104 was not found on this server. That’s all we know.