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Version: 3.1.X

Verb: ListIdentifiers

Retrieves a list of headers (identifiers and datestamps) but not the full metadata records. This is used by harvesters to check for updates (using from and until dates) before downloading heavy payloads.

  • Usage: ?verb=ListIdentifiers&metadataPrefix=oai_dc
  • Compulsory Parameters: metadataPrefix.
  • Optional Parameters: set, from, until, resumptionToken.

Identifier Structure​

The OAI Identifier format depends on your database configuration (identifier_field in oai.conf):

  • Case 1 (Numeric ID): If mapped to Tag 1 (Control Number):
    • oai:repository:db_name-123
  • Case 2 (String ID): If mapped to a string field (e.g., Accession No):
    • oai:repository:db_name-NEG100-002

Pagination (ResumptionToken)​

If the database is large, ABCD will not return all IDs at once. It returns a batch (e.g., 100) and a resumptionToken. The harvester must make a new request with this token to get the next batch.

Critical Configuration Warning

If the CISIS version (cisis_ver in config.php) is not compatible with your database files, this verb might return a valid header but empty identifiers. The interface might show a single header with missing data. Always verify if your IDs are appearing correctly.