pbcoreExtension is an extension element. Extensions are either a wrapper containing a specific element from another standard OR embedded xml containing the extension.

Best practice: Use it to supplement other metadata sub-elements of the PBCore description document in which it appears

pbcoreExtension can be contained by the elements pbcoreDescriptionDocument or pbcorePart.

Usage: optional, repeatable.


pbcoreExtension has no attributes.


instantiationExtension contains the following subelements:

  • extensionWrap – required ONLY if extensionEmbedded is not used. The extensionWrap serves as a container for the elements extensionElement, extensionValue, and extensionAuthorityUsed..
  • extensionEmbedded – required ONLY if extensionWrap is not used. The extensionEmbedded element allows the inclusion of xml from another schema, e.g. TEI, METS, etc.


Submit any issues or suggested changes for future schema iterations by creating a ticket in our Github repository.