Note that the index numbers are only technical numbers which have no persistence. After a new system generation is done, all of them are invalid. To generate a persistent link, use the name.Use the URL:
http://ww-person.com/cgi-bin/l3/LANG=fran/F=Matthieu@V/N=de@Montmorency,@d'Ecouen@et@de@Damville
Matthieu V de Montmorency, d'Ecouen et de Damville
alternatively: /cgi-bin/llmult/LANG=germ/P=6003713