Library and Archives Canada (LAC) has committed to a multi-year project to become a Trusted Digital Repository (TDR).   First, it outlined how it is building a TDR that is based on the Open Archival Information Systems (OAIS) Reference Model.  The project explanation has several handy diagrams to help explain digital preservation processes, like this one that shows LAC’s metadata flow:

Library and Archives Canada TDR Metadata Flow

And last week, it released File Format Guidelines for Preservation and Long-Term Access (Version 1.0).  These guidelines “serve as the policy foundation for LAC’s Local Digital Format Registry (LDFR), the underpinning set of guidelines for file format normalization/migration services within LAC’s TDR.”  But they were developed for a wide audience, including the public, academic and private sectors, so they’re worth a look from anyone seeking guidance on long-term preservation of electronic records.

The Guidelines identify the file formats that LAC will be supporting in the TDR.  It divides them into “Recommended” formats and formats that are “Acceptable for Transfer” and explains a comprehensive evaluation and rating system that was used to assess formats.  Table 3 lists a variety of content types (e.g., text, audio, structured data, etc.) and their Recommended and Acceptable for Transfer formats.  Table 4 summarizes the evaluation of Recommended formats.

The document also explains LAC’s digital content preservation strategy:

• When digital content is first accepted/approved for preservation in the TDR (that is, the content has been evaluated by LAC and deemed to be of preservation value), a preservation master is created (termed a “preservation master (0)” or PM(0));
• As part of the acceptance/approval process, the digital content is normalized as required (that is, migrated from the submitted/transferred format to one of the appropriate recommended preservation formats), thereby creating a new preservation master (termed a “preservation master (+1)” or PM(+1));
• From the current preservation master (i.e., PM(0) or PM(+1)), a copy of the digital content is created to service access requests by internal and external users (termed a “service copy”);
• The service copies can be presented using LAC-supported play-out services as well as client-based play-out services where needed or desired (an example of a play-out service would be an Apache server for HTML pages combined with a browser on the client, or a video streaming server; on the client, the Adobe Reader is an example of a client-based play-out service).

The TDR project document concludes by listing LAC’s priorities for the coming year:

• Defining the architecture of its TDR (post-SIP)
• Implementing the first iteration of a complete TDR for digital publications
• Implementing the ingest service for Government Archives
• Investigating the possibility to use the GCWA service as a means for Government Legal Deposit
• Integrating mass digitization efforts to the VLD/TDR

The pair of documents are a nice addition to information about digital preservation, so hopefully LAC continues to update on its progress.