Module C3: File Formats & Metadata

Module Status: Drafting in Progress | Ready for Testing | Tested
Current Module Downloads: Module C3 Activity Worksheet

The areas addressed by this module focus on creating work in stable, sustainable formats and also making sure that these formats, as well as the rest of your project, are well-documented. The file formats section makes recommendations for creating files in formats that will support long-term access. The metadata section prompts you to think even more broadly about documenting your project, including its socio-technical components and associated workflows.

File Formats

While the specifics may vary from project to project, in general, whenever possible, you will benefit from creating digital files in open formats, which tend to better promote long-term accessibility and support. As the levels of this area intensify, recommendations include additional documentation strategies such as creating a master inventory of all file formats used within a project, as well as the work of technological migration and emulation when needed—as might be the case when a project is built in a language or platform that is no longer supported by modern operating systems or browsers. When working through the File Formats section, you should not only consider the formats of individual files, but also the software you will need to render those files, including any original code being used in your work.

Level 1 Level 2 Level 3 Level 4
File Formats When possible, create files using a limited set of known open file formats Maintain an inventory of all file formats used in your project Routinely monitor your file formats for obsolescence issues Perform format migrations, emulations, and other updating activities as needed


This section uses a flexible, inclusive definition of metadata, which comprises information about file creation and file locations, as well as descriptive data about your project, including preservation information. Central to this area of sustainability is an understanding of what types of descriptive information is or can be associated with your files and technologies and the assurance that this information will be useful to current and future project team members, or even potential future project stewards.

Recordkeeping and descriptive metadata are included at Level 1, and with each level, additional metadata layers are incorporated. Definitions of each of the types of metadata identified in this section are also available in the STSR glossary.

Depending upon the specifics of your project, not every type of metadata is necessary, or even desirable, so this is an area of sustainability in which the levels are not necessarily cumulative. For a more detailed introduction to the world of metadata, project teams may find Jenn Riley’s Understanding Metadata: What is Metadata and What is it For? helpful.

At Levels 1 and 2, some understanding of open and stable file formats is also required. The Library of Congress Recommended Formats Statement may be useful to teams working to meet the requirements of these first levels. Because open formats are preferred for preservation purposes, no specialized proprietary software is necessarily required.

You may also notice that if you completed the recordkeeping exercises in Module A5, you are well on your way to completing Level 1 in this area of sustainability. Moreover, if your team felt that the Level 2 sustainability practices in Module C2: Access were important to your project, you will also have decided to create and store descriptive metadata, placing the Level 1 sustainability practices directly within reach.

Level 1 Level 2 Level 3 Level 4
Metadata Document your reliable sites of project documentation including a description of their contents

Create and make available descriptive metadata, such as title, abstract, keywords, or other information that is useful for discovery

Maintain an inventory of all file formats used in your project

Maintain an inventory of file sizes for static files

Store administrative metadata, such as when files were created and with what technologies Store transformative metadata, such as a log of how files have been altered over time

Store standard preservation metadata

Additional Resources

Owens, Trevor. “Arranging and Describing Digital Objects.” In The Theory and Craft of Digital Preservation, 85-103. OSF Preprint. Accessed September 23, 2022.

Potter, Abbey. “Seeking Comment on Migration Checklist.” Library of Congress The Signal Blog. September 3, 2015.

“Recommended Formats Statement.” Library of Congress. Accessed September 23, 2022..

Riley, Jenn. “Understanding Metadata: What is Metadata and What is it For?” National Information Standards Organization. 2017.

(Module last updated September 2022)

Previous Module: Module C2: Access & Backing Up Your Work Next Module: Module C4: Permissions & Data Integrity
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