OID value: 0.9.2342.19200300.100.1.11
OID description:
The Document Identifier attribute type specifies a unique identifier
for a document.
documentIdentifier ATTRIBUTE ::= {
    WITH SYNTAX DirectoryString { ub-document-identifier }
    EQUALITY MATCHING RULE caseIgnoreMatch
    SUBSTRINGS MATCHING RULE caseIgnoreSubstringsMatch
    ID id-documentIdentifier
}
See also the OID Repository website reference for 0.9.2342.19200300.100.1.11