The history of PDF/UA

PDF/UA in a Nutshell

The first version of PDF, PDF 1.0, was released in 1993. PDF was created and further developed by Adobe Systems Incorporated. The PDF format makes it easier to exchange and display digital documents; in the two decades since its publication, it has gained worldwide acceptance. It allows all kinds of documents to be reproduced exactly as they were originally designed, regardless of the platform used, thanks to a number of (sometimes free) PDF creation and viewing programs and web browser plug-ins.

For a long time, however, this file format remained inaccessible to a large number of people, as PDF originally focused on the visual presentation of a document rather than its content and structure. In order to address this problem, in 2001 Adobe introduced tags with PDF 1.4 and Adobe Acrobat 5. These can be used to turn a conventional PDF into a tagged PDF.

In 2004, a working group began to form, coordinated by AIIM (the Association for Information and Image Management, www.aiim.org), aiming to develop a universally accessible PDF standard. This standard would specify a complete set of requirements for tagged PDF documents that could be reliably used to create and check for a sufficient level of accessibility.

A further important development came in 2008, when Adobe’s PDF 1.7 specification became an ISO standard – published by the ISO as “ISO 32000-1:2008. Document management – Portable document format – Part 1: PDF 1.7”. A copy of the standard can be downloaded for free from the Adobe website, while the ISO version (which is identical in content) can be ordered from ISO for a fee. Also in 2008, the World Wide Web Consortium (W3C) published WCAG 2.0. This replaced its predecessor WCAG 1.0, published in 1999, and took into account the technical developments which had taken place since that time.

An ISO standardisation project began in 2009. Based on AIIM’s project, ISO committee ISO TC 171 SC  2, chaired by Cherie Ekholm of Microsoft, aimed to further develop PDF/UA. A wide range of companies, including Adobe, Microsoft, callas software, Appligent, Design Science, NetCentric and others were actively involved in the standardisation work. This meant that just one year later, the draft standard ISO/DIS 14289-1 was ready for publication. After an intensive consultation and testing phase, PDF/UA was finally approved as an ISO standard and published as ISO 14289-1 in July 2012.

The German standardisation organisation DIN (Deutsches Institut für Normung e.V.) is currently working on translating ISO 14289-1 into German; this version is expected to be published in autumn 2013.

On the international stage, meanwhile, the second part of the standard (PDF/UA-2) is now being prepared by the ISO. PDF/UA-2 will be based on the next version of the PDF format, PDF 2.0, and will make use of all that has been learned during the development and introduction of PDF/UA-1. Among other things, it will include more extensive options for sophisticated semantic structuring of content and support for specific tag sets. These will include scientific sets, such as MathML and ChemML, as well as specialised publication tag sets such as DAISY and DocBook.

Timeline: From PDF to PDF/UA

  • 1993: Adobe Systems publishes PDF 1.0
  • 1999: W3C releases Web Content Accessibility Guidelines 1.0
  • 2001: PDF 1.4 integrates tags to represent the logical structure of content within PDF documents
  • 2002: Equal Treatment of Disabled Persons Act, Germany
  • 2002: Accessible IT Regulation 1.0, Germany
  • 2004: PDF/UA project begins, coordinated by AIIM
  • 2008: PDF 1.7 published as an ISO standard (ISO 32000)
  • 2008: UN Convention on the Rights of People with Disabilities comes into effect
  • 2008: W3C releases Web Content Accessibility Guidelines 2.0
  • 2009: ISO takes over the PDF/UA project as ISO/NWI 14289
  • 2011: 
Accessible IT Regulation 2.0, Germany
  • 2012: ISO approves and publishes PDF/UA (ISO 14289-1)
  • 2012:  ISO verabschiedet und veröffentlicht PDF/UA (ISO 14289-1)

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About PDF Association

Founded in 2006 as the PDF/A Competence Center, the PDF Association exists to promote the adoption and implementation of International Standards for PDF technology.

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