Vulnerable small

Materials contained within PDF/A; a format derived from the PDF 1.4 variant but with additional requirements that reduce external dependencies. Includes more recent variants (PDF/A2 and PDF/A3)

Group: Formats

Trend in 2021:

Consensus Decision

Added to List: 2017

reduced riskTrend towards reduced risk

Previous classification: Vulnerable


Trend in 2022:


No changeNo Change


Imminence of Action

Action is recommended within five years, detailed assessment within three years

Significance of Loss

The loss of tools, data or services within this group would impact on people and sectors around the world.

Effort to Preserve

It would require a small effort to preserve materials in this group, requiring the application of proven tools and techniques.


Documents stored offline, or online in repositories or EDRMS including as reports, agenda, minutes, correspondence, contracts, essays, articles, or research papers.

‘Endangered’ in the Presence of Aggravating Conditions

Lack of conformance or validation; Lack of preservation commitment or planning; Lack of storage replication; Poor management of data protection or intellectual property rights; Political or commercial interference; loss of version control; use beyond the design capability of the standard; complacency; poor metadata; disassociation from context; loss of authenticity; encryption.

‘Lower Risk’ in the Presence of Good Practice

Backup and documentation of media assets; validation on creation; part of preservation plan; export functionality; licencing enables preservation; preservation capability in repository or EDRMS service; resilient to hacking; selection and appraisal criteria; version control; authenticity; resilient funding and recognition of value; technology watch

2021 Jury Review

This entry was added in 2017. PDF/A has become more stable and reduces dependencies, and thus curtails preservation risks for certain types of content.
The 2021 Jury agreed and added that there is also now PDF/A-4, moving towards reduced risk. However, this alone is not sufficient to ensure preservation, and therefore users should be warned against complacency. PDF/A has sometimes been misunderstood or misrepresented as a generic solution to all digital preservation requirements. In the eyes of the BitList Jury members, it can only offer a preservation solution when embedded within a wider preservation infrastructure

Additional Jury Comments

Vulnerability also depends on if the PDF file conforms to the specific PDF/A standard or not. This is caused by a combination of 1) not conforming to the standard and 2) collection managers assuming that the file is resilient simply because it purports to be a PDF/A. This risk is less with the format and more with the understanding and experience in data management. Moreover, materials embedded in or attached to PDF/A-2 and PDF/A-3 may be at risk.

See also: Fanning, B (2017) Preserving with PDF/A (Second Edition), DPC Technology Watch Report 17-01 online at

Scroll to top