PDF / UA

from Wikipedia, the free encyclopedia

PDF / UA (Universal Accessibility; English for "universal access") is a substandard of is PDF standards (ISO 32000-1) for accessible PDF documents. It was published in August 2012 as ISO standard ISO 14289-1: 2012-07 (Document management applications - Electronic document file format enhancement for accessibility, Part 1: Use of ISO 32000‑1 [PDF / UA-1]), Revised in 2014 as ISO 14289-1: 2014.

PDF / UA defines how the PDF standard is to be used so that a PDF document can meet the requirements for accessibility. The specifications of PDF / UA are based on the requirements of the Web Content Accessibility Guidelines 2.0 (WCAG; English for "guidelines for barrier-free web content"). The guidelines describe the nature of accessible web content, make numerous recommendations and formulate testable, non-technology-specific success criteria. In contrast, PDF / UA defines the technical requirements for barrier-free PDF documents based on the PDF standard. These requirements provide a quality standard for accessible PDF documents and also provide orientation for the development of compliant display or processing programs and compliant assistive technologies .

The requirements for a PDF / UA-compliant, accessible document are made up of the technical and content properties of the PDF file. A central aspect here is marking the relevant content with PDF tags. The Matterhorn Protocol is available to users for implementation . The Matterhorn protocol consists of 31 test points with a total of 136 error conditions (criteria for conformity). The error conditions are divided into 87 criteria that can be tested by software and another 47 criteria to be tested by human testers (2 test criteria are not assigned). The requirements largely coincide with WCAG 2.0. However, not all requirements from the WCAG have been adopted and in some places additional or slightly different requirements are formulated.

The Tagged PDF Best Practice Guide: Syntax was created for the development of PDF / UA-compliant software .

Numerous tools are available for checking PDF / UA conformity, such as: Preflight from Adobe Acrobat DC (according to PDF / UA from version April 2017), PDF Accessibility Checker (PAC), Callas pdfaPilot , axes QuickFix , CommonLook PDF Validator .

Screen readers do not yet specifically support PDF / UA . The PDF Association , together with the Swiss Foundation for Access for All, has therefore launched the NVDA goes PDF / UA project to further develop the NVDA open source screen reader so that it fully complies with the PDF / UA standard.

literature

  • Markus Alder. PDF without borders: structure PDFs cleanly - avoid access barriers . c't 9/2012, pp. 180-183.
  • Olaf Drümmer, Bettina Chang, PDF / UA compact . PDF Association. 2013/08
  • Klaas Posselt, Dirk Frölich: Creating barrier-free PDF documents - the practical manual for everyday work . 1st edition. dpunkt Verlag, Heidelberg 2019, ISBN 978-3-86490-487-5 ( approx. 40 pages of reading samples [accessed on June 27, 2019]).

Web links

Individual evidence

  1. ISO standard PDF / UA. In: access-for-all.ch. "Access for All" foundation, accessed on June 28, 2019 .
  2. ^ WCAG 2.0, Authorized German Translation. In: Web Content Accessibility Guidelines (WCAG) 2.0. W3C, December 11, 2008, accessed June 28, 2019 .
  3. ^ The Matterhorn Protocol 1.02. In: pdfa.org. PDF Association, April 3, 2014, accessed June 28, 2019 (American English).
  4. Tagged PDF Best Practice Guide: Syntax. In: PDF Association. Retrieved June 11, 2019 (American English).
  5. NVDA goes PDF / UA! The PDF Association Steps Up to Fund Development of the World's First PDF / UA Conforming Screen Reader. In: pdfa.org. PDF Association, June 28, 2012, accessed June 27, 2019 (American English).