The RISM library abbreviations, or sigla, are used for identifying locations of musical manuscripts. The special volume RISM-Bibliothekssigel. Gesamtverzeichnis (RISM Library Sigla. Complete Index), which appeared in 1999, has been available in a regularly updated version on the RISM website since 2006 and in a searchable database online since 2011.[1]
The complete list is very long (see pdf). Only a selection of major source locations are listed here:
it:Curia Arcivescovile di Ferrara e Comacchio, Archivio
I-MOas