Collection in Codex Trivisanus
From Clavis Canonum
Venezia, Archivio di Stato, Secreta, Codice Trevisaneo (or Codex Trivisanus) contains a vast collection of charters (including papal letters) copied from various Venetian archives. It has been used among other scholars by Pertz (when it was still in Vienna), Kaltenbrunner, Gundlach (via transciptions by Holder-Egger), but not Kehr, for their editions of papal letters; likewise, it has been used by MGH and RI scholars to study royal and imperial diplomas.
Literature
Domenico M. Pellegrini, Indice ragionato dei diplomi contenuti nel codice Trevisaneo. In: Giornale dell'italiana letteratura 17 (1807) pp. 3-32, 113-144, 225-256, online; Kaltenbrunner SB Wien 94 (1879) pp. 644-645 (list of papal letters by Jaffé numbers); Gundlach MGH Epp. 3 p. 691
