Recommended Formats Statement 2025-2026
The Recommended Formats Statement (RFS) is well into its second decade, having first launched in 2014. It remains an important tool for both the Library of Congress but also the wider community who seek to create, collect and preserve published works in all forms. The resource has evolved over its lifespan to reflect not only changing priorities and capabilities but also its impact on the cultural landscape.
Digital Accessibility as an Evaluation Criterion
Since 2024, the RFS incorporates a preferred or acceptable format's potential to support digital accessibility as an evaluation criterion. These features include:
- Does this format support digital accessibility features such as those described in the W3C Accessibility Principles? For example,
- Text alternatives for non-text content (such as alt text)
- Captions and other alternatives for multimedia (and subtitles)
- Can text content be structured (as in XML) or tagged (as in PDF) for screen readers?
- Are dataset formats well-structured with page regions and headings identified, permitting tagged or marked up content, tables that are navigable to a screen reader and forms that can validate entries?
- In what way are accessibility features implemented in the format? Such as:
- Are there specific metadata tags to indicate accessibility features such as alt text, captions, transcripts and the like?
- Are embedded closed captions supported? Does the file rely on external data, such as WebVTT file for caption data?
Full details about the information gathering and reporting are available on Documenting Accessibility Features on the Sustainability of Digital Formats. Each format listed in the RFS has a corresponding entry on this resource with supporting in depth research.
It’s important to note that the RFS does not require these accessibility features to be enabled for a format for inclusion in LC collections. However, but it is still important to understand the capacity for the format to support these features as user expectations and communities change and grow.
Content Category Changes For 2025-2026
This year brings several changes to the RFS, especially with Design and 3D. A few adjustments were made to listed formats to better focus on formats related to design and the built environment and reduce overlap with formats more geared toward GIS and geospatial data. And a definition about the scope of this content area was added in response to user feedback.
Another reflective change is in metadata for Email collections. These elements better align with those outlined in the recently published EA-PDF v.1.0 specification which is a vendor- and platform- neutral format for the long-term preservation of email based on PDF/A.
The Moving Image section also sees some changes as the technology evolves away from physical media like commercially pressed DVD or Blu-ray disc to file-based data carriage.
A full list of all changes is shared in the Change Log available on the RFS home page.
Preferred and Acceptable Formats
The key underpinning to the RFS remains a focus on both global/community criteria and local/institutional criteria as key to preservation and long-term access. The global/community criteria have been based on the seven sustainability factors developed for the Library’s Sustainability of Digital Formats website: Disclosure, Adoption, Transparency, Self-documentation (including accessibility support), External dependencies, Impact of patents and Technical protection mechanisms. Each of these factors may have different emphasis or importance depending on the community of practice and content type. Some may not be applicable or essential for every format. The local/institutional factors estimate the level of resources at The Library of Congress available to preserve and manage the content over time. These include Staff experience and expertise, Software/Hardware/Operating System availability, Representation/extent in LC collections/storage, Established workflow/functionality and Access options including support on the Library’s website, loc.gov. The outcome of this analytical structure are clearer definitions of ‘Preferred’ and ‘Acceptable’ when categorizing digital file formats in the RFS.
The evaluation matrix with sample data is available for download.
Preferred formats:
- Global/community: Meets or exceeds benchmarks for all relevant sustainability factors
- Local/institutional: The Library of Congress has the skills, experience, workflows, tools and systems to manage and preserve these formats in current systems with confidence.
Acceptable formats:
- Global/community: Meets minimum acceptability across benchmarks or does not meet all relevant sustainability factors.
- Local/institutional: The Library of Congress can manage this format at a basic level of acquisition, management and preservation; and a greater ability for management and preservation is within the Library’s capacity with further investment.
The success in using this model opens the possibility of adapting it to apply to those other characteristics of creative works, both physical and digital, which the RFS covers in its remit to address all types of creative works.
The Recommended Formats Statement is not intended to serve as an answer to all the questions raised in preserving and providing long-term access to creative content. For example, it does not provide instructions for receiving material into repositories, managing that content or undertaking the many ongoing tasks which will be necessary to maintain this content so that it may be used well into the future. Tackling each of those aspects is a project in and of itself as each form of content has a unique set of facets and nuances. The RFS provides guidance on identifying sets of formats which are not drawn so narrowly as to discourage creators from working within them, but will instead encourage creators to use them to produce works in formats which will make preserving them and making them accessible simpler. See the FAQ page for additional context. The Library hopes that the RFS will help make it realistic to build, grow and save creative output for our individual and collective benefit for generations to come.
Conclusion
The Library of Congress, realizing its unique position, is pleased to be able to contribute a resource like the Recommended Formats Statement for the benefit of all involved with creative works. The commitment of time and resources to the ongoing revision and indeed improvement of the RFS reflects the priority the Library places on working collaboratively to ensure that all might succeed in our common goal to share and disseminate creative output and to benefit the nation and the world at large. Comments are always welcome through [email protected].
