Glossary Updates6 new terms added to the glossaries · October 11, 2026, 13:38 CEST
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Glossary · Versions and files

PDF/A

Also known as: ISO 19005, PDF/A-1, PDF/A-2, PDF/A-3, PDF/A-4, archival PDF

PDF/A is the ISO 19005 family of standards for a constrained form of PDF intended for the long-term preservation of page-oriented documents: a PDF/A file must be self-contained — with all fonts embedded and standards-based metadata — and must not use features such as encryption, JavaScript or external content that would endanger a faithful rendering in the future.

  • Information architecture
  • Standards
  • Technical documentation

In one sentence

PDF/A (ISO 19005) is the archival form of PDF — self-contained, fonts embedded, no encryption — and the base format required by VDI 2770 and iiRDS/H.

Example

A manufacturer exports its operating instructions as PDF/A-3u, so that every character can be searched, and embeds the original spreadsheet of the spare parts list as an associated file.

How it applies

Part Standard Based on Conformance
PDF/A-1 ISO 19005-1:2005 PDF 1.4 Levels a and b
PDF/A-2 ISO 19005-2:2011 PDF 1.7 (ISO 32000-1) Levels a, b and u; PDF/A files may be embedded
PDF/A-3 ISO 19005-3:2012 PDF 1.7 (ISO 32000-1) Levels a, b and u; files of any format may be embedded as associated files
PDF/A-4 ISO 19005-4:2020 PDF 2.0 (ISO 32000-2) No levels; profiles PDF/A-4f (embedded files) and PDF/A-4e (engineering documents)
  • Constraints: For PDF/A-1 to PDF/A-3, audio, video, 3D artwork, JavaScript and executable launches are forbidden, all fonts must be embedded, color spaces must be device-independent, encryption is not allowed and XMP metadata are mandatory. Level a adds a tagged logical structure, level u requires Unicode text, level b secures the visual appearance only. PDF/A-4 relaxes some rules, for example for JavaScript stored in embedded files.
  • VDI 2770: Each document version must be supplied at least as one PDF/A file; the guideline cites PDF/A-2 and PDF/A-3 among its normative references, and implementations such as the AAS Handover Documentation submodel also accept PDF/A-1. Native files may be added alongside.
  • iiRDS: iiRDS/H requires at least one PDF/A rendition per document and allows PDF/A-2a, PDF/A-2u, PDF/A-3a and PDF/A-3u. iiRDS/A requires PDF/A-3 for non-structured text and allows it for structured text, next to iiRDS XHTML5.
  • Why the handover standards require it: Operators keep manufacturer documentation for the whole lifetime of a plant, often several decades. PDF/A ensures that a file can still be displayed in the same way with standard software long after the authoring tool is gone.
  • Validation: A file named .pdf is not PDF/A because it says so. Check conformance with a validator before delivery; a PDF printed from a scan is at best level b and needs text recognition to be searchable.

PDF/A vs. native file

PDF/A is the frozen, page-based rendition for reading and archiving. A native file — the spreadsheet, CAD model or authoring source — keeps the data editable and machine-processable but depends on the software that reads it. VDI 2770 and iiRDS/H therefore require PDF/A as the mandatory rendition and allow native files only in addition, with the same content. PDF/A-3 can carry the native file inside the PDF as an associated file.

External references