Endangered large

Documents presented in PDF (Portable Document Format) format (ISO 32000:1 and ISO 32000:2) and other data wrapped inside them, other than PDF/A but including all other variants and versions.

Group: Formats

Trend: No change

Consensus Decision

Added to List: 2017

Last update: 2018

Previous category: Of Concern

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 address losses in this group, requiring the application of proven preservation tools or techniques.


PDF 1.1, 1.2, 1.3, 1.4 (excluding PDF/A as a subset), 1.5, 1.6, 1.7 and 2.0. PDF/X and PDF/E

‘Critically Endangered’ in the Presence of Aggravating Conditions

Loss of context; loss of authenticity or integrity; external dependencies; poor storage; lack of understanding; significant diversity of data; poorly developed digitization specifications; lack of integrity checking; poorly developed migration or normalizations specifications; lack of virus control; poor storage or replication; lack of validation at the point of creation; encryption.

‘Vulnerable’ in the Presence of Good Practice

Well managed data infrastructure; preservation planning; authenticity managed; use of persistent identifiers; reduction of dependencies; application of records management standards; recognition of preservation requirements beyond formats; strategic investment in digital preservation; preservation roadmap; participation in digital preservation community; format validation.

2019 Review

The judges have introduced this entry as a subset of a previous entry for ‘PDF’, emphasizing the different threats faced by different types of PDF. PDF/A explicitly reduces dependencies and thus curtails preservation risks for certain types of content: PDFs of other types do not. PDF and PDF/A have sometimes been misunderstood as a generic solution to digital preservation requirements. In the eyes of the judges it can only offer a preservation solution when embedded within a wider preservation infrastructure.

Additional Jury Comments

See also:

Fanning, B (2017) Preserving with PF/A (Second Edition), DPC Technology Watch Report 17-01 online at http://dx.doi.org/10.7207/twr17-01

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