But if the shelfmark has changed and HMML was not notified, this is not reflected in the catalogue record. Try former shelfmarks and notify HMML of any new ones. If the manuscript changed hands since then and HMML was not notified, this is not reflected in the catalogue record. Use the City drop-down menu to narrow your search. If the name of the library is not in the drop-down menu, HMML does not have any manuscripts from that library.
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Use the Library drop-down menu to narrow your search. Try entering more than one version or spelling of an author's name for best results. This is not linked with In Principio. The incipit data is incomplete in this early version of the catalogue. It is possible to search for an exact year or century.