When the SIP is first deposited into the repository, SP's customized loader script decompresses it and records the file fixity information. All of the Provider provided metadata for each file, including the PDI, is extracted and normalized to version 3.0 of the NIH Journal Archiving & Interchange Tag set and housed in the eJournals database. Each AIP is given a unique URI. From there it is accessed by the TDR loader script which creates the Preservation Metadata. SP Preservation Metadata for each AIP contains the Reference Information (URI), the Context Information (Provider provided bibliographic information and SP created linkages, TOCs, etc.), Fixity Information, and Provenance Information (created by SP in PREMIS vocabulary as 'events').
For a visual representation of these procedures please see the document below.
Digital Preservation Policy Librarian