Deep Blue Preservation and Format Support Policy

Deep Blue (hereafter the "Repository") is committed to providing long-term access to all deposited content by applying best practices for data management and digital preservation while also acknowledging the complexities involved in preserving digital information. The Repository commits to preserving the content in the form it is originally deposited and, for some formats, will preserve the content, structure and functionality of the files through migration or other preservation strategies. In addition, the Repository will provide basic services including secure storage, backup, management, fixity-checks, and periodic refreshment by copying the data to new storage media.

At the outset, the Repository will provide three levels of preservation support for specific file formats. We have determined these support levels by applying a set of evaluation criteria including prevalence of the file format in the marketplace, whether the format is proprietary, the availability of tools for emulation or migration and the availability of local resources to take specific preservation actions. The Repository will undertake appropriate format monitoring and provide adequate staffing and other resources to support the services offered at each level. Over time, our ability to provide full preservation support for more formats is likely to grow as additional tools and techniques are developed. To assist content creators in saving and depositing documents that meet the level of quality necessary for full information capture and the highest degree of preservability over time, Deep Blue is developing a set of specification and format best-practice guidelines for common content types.

The Repository provides three levels of support for various submission file formats.

Level 1

The Repository will provide its highest level of preservation support, making its best effort to maintain the content, structure and functionality in the future. This service level is currently provided only for formats that are both publicly documented and widely used, giving us a high degree of confidence in our preservation commitment, making it more likely that tools will exist or be developed to undertake preservation actions, and that those actions will result in an understood and controlled transformation or migration. The content may also be normalized (transformed to another stable format) to provide additional assurance that the information content is preserved. Finally, the content will be preserved as originally deposited to ensure the original bitstream is always available. TIFF is an example of a Level 1-supported format, as its specifications are publicly available, it is well-supported and widely deployed.

Level 2

The Repository will make limited efforts to maintain the usability of the file as well as preserving it as submitted (bit-level preservation). The format will be monitored and may be transformed when significant risk to access is imminent but it is likely to be difficult to predict or control the consequences of any transformation or migration on content, structure or functionality. The file may also be transformed to a more preservable format to ensure that the information content is not lost, even if some structure and functionality are sacrificed. This level of support is generally applied to proprietary formats that are widely used, where there is substantial commercial interest in maintaining access to files saved in the format, and therefore tools will likely be available to migrate them to successor formats (e.g., Microsoft Word).

Level 3

The Repository provides basic preservation of the file (bitstream) and associated metadata as-is with no active effort made to monitor the format and associated risks or to normalize, transform or migrate the file to another format. Files may be openable and/or readable by future applications, but there is no guarantee that the content, structure, or functionality will be preserved. This service level usually applies to files written in highly specialized, proprietary formats, often usable only in a single software environment, formats no longer widely utilized, and/or formats about which little information is publicly available. PhotoCD is an example of a format that would receive Level 3 support in the Repository. Any format not yet reviewed and evaluated by Deep Blue will also receive Level 3 service on deposit. A higher level may be assigned after format review takes place.

The following chart summarizes the primary preservation services that Deep Blue will provide at the various service levels:

The three levels of preservation commitment are made at the individual file level. Complex content items comprised of multiple files in various formats will need additional evaluation to determine whether the operational relationships between the files can be maintained. If the original relationships are documented externally in metadata, that information will be preserved in any case. In addition, executables and some files that rely on a specific hardware/software environment will require additional evaluation because not only the format but the access environment must be considered in making a preservation determination. Because of the collection policy for accepting finished work, we discourage submissions in some "working" formats, such as Photoshop and Final Cut Pro, since we will be unable to offer the highest level of preservation support for them. If you have material to deposit that fall into any of these categories, please contact the Deep Blue Preservation Group prior to making your deposit.

Registered Formats and Support Levels

This list of formats and support levels will be regularly reviewed and update based on our growing experience with digital preservation and the emergence of new formats and standards.

Last updated March 9, 2011