The <msIdentifier>

Traditional three part specification:

• place (<country>, <region>, <settlement>)
• repository (<institution>, <repository>)
• identifier (<collection>, <idno>)

plus alternative names tagged with <altName> and/or former shelfmarks tagged with <altIdentifier>

<msIdentifier>
  <country>France</country>
  <settlement>Troyes</settlement>
  <repository>Biblioth&egrave;que Municipale</repository>
  <idno>50</idno>
  <altName type="IRHT">Medium 27178</altName>
</msIdentifier>