The repository shall have documented processes for acquiring Preservation Description Information (PDI) for its associated Content Information and acquire PDI in accordance with the documented processes.

This is necessary in order to ensure that an auditable trail to support claims of authenticity is available, that unauthorized changes to the digital holdings can be detected, and that the digital objects can be identified and placed in their appropriate context.

Standard operating procedures; manuals describing ingest procedures; viewable documentation on how the repository acquires and manages Preservation Description Information (PDI); creation of checksums or digests, consulting with Designated Community about Context.

PDI is needed not only by the repository to help ensure the Content Information is not corrupted (Fixity) and is findable (Reference Information), but to help ensure the Content Information is adequately understandable by providing a historical perspective (Provenance Information) and by providing relationships to other information (Context Information). The extent of such information needs is best addressed by members of the Designated Community(ies). The PDI must be permanently associated with Content Information.

The preservation metadata is parsed from the tag files described in the APT BagIt profile. Some of the metadata like timestamp of ingest and when identifier was assigned are PREMIS events generated upon ingest. Also see:

• Bagging specifications
• Ingest documentation