An identifier, such as a DOI, archive control number, or LCCN for a series or set of books.
The @collection-id-type attribute should be used to name the type of identifier, such as an “lccn”. There is a separate element for any ISBNs (<isbn>) related to a collection.
<!ELEMENT collection-id (#PCDATA) >
Text, numbers, or special characters
No sample is available at this time.