<msIdentifier> is used to record the manuscript's siglum, as assigned for use in the Carolingian Canon Law project. The siglum must begin with an uppercase letter: e.g., Wur22 for Wuerzburg, Universitaetsbibliothek, M.p.th.f.22; C1525 for the Cochlaeus 1525 edition of the Collectio Dionysio-Hadriana. The list of CCL sigla may be found on the CCL website in the Collection List. In the <msIdentifier> tag, the siglum is expressed as a unique xml:id, e.g.: <msIdentifier xml:id="Hat42">.

In the <msIdentifier> section:

<settlement> records the city or town in which the manuscript is currently located.

<repository> records the repository, usually a library, in which the manuscript is currently stored.

<collection> records the name of the manuscript if the manuscript is part of a collection, i.e. fond.

<idno> is used to indicate the standard identifier for the manuscript, usually a shelfmark.