PDF/UA

Last updated
PDF/Universal Accessibility
Filename extension
.pdf
Type code 'PDF ' (including a single space)
Magic number %PDF
Developed by ISO
Initial release15 July 2012 (2012-07-15)
Latest release
Part 1:2014
18 December 2014;9 years ago (2014-12-18)
Extended from PDF
Standard ISO 14289

PDF/UA (PDF/Universal Accessibility), [1] formally ISO 14289, is an International Organization for Standardization (ISO) standard for accessible PDF technology. A technical specification intended for developers implementing PDF writing and processing software, PDF/UA provides definitive terms and requirements for accessibility in PDF documents and applications. [2] For those equipped with appropriate software, conformance with PDF/UA ensures accessibility for people with disabilities who use assistive technology such as screen readers, screen magnifiers, joysticks and other technologies to navigate and read electronic content. [3]

Contents

On February 18, 2015 the US Access Board announced its Proposed Rule for US federal policy on accessibility, commonly known as Section 508. The proposed rule identifies PDF/UA as equivalent to WCAG 2.0 for "appropriate content". [4]

Description

PDF/UA is not a separate file-format but simply a way to use the familiar PDF format invented by Adobe Systems and now standardized as ISO 32000. [5]

In general PDF/UA requires Tagged PDF (ISO 32000-1, 14.8), but adds a variety of qualitative requirements, especially regarding semantic correctness of the tags employed: [6] [7]

PDF/UA complements WCAG 2.0, [8] and should be used to make PDF files that also conform with WCAG 2.0. [9]

The 2014 update to PDF/UA, published in December 2014, is the first fully accessible standard ISO has ever published; the PDF file distributed by ISO itself conforms to PDF/UA. [10]

Requirements for conforming PDF files (Clause 7)

Requirements for conforming PDF processors (Clause 8)

Requirements for conforming assistive technology (AT) (Clause 9)

The formal name of PDF/UA is "ISO 14289-1 Document management applications -- Electronic document file format enhancement for accessibility -- Part 1: Use of ISO 32000-1 (PDF/UA-1)". [11]

Audience & Benefits

While the PDF/UA specification is written for software developers, PDF/UA support is of interest to persons with disabilities who require or benefit from assistive technology when reading electronic content. With PDF/UA conforming files, readers and assistive technology, users are guaranteed – so far as the PDF format itself can provide – equal access to information.

The benefits of PDF/UA extend beyond people with disabilities. With support for PDF/UA, reader software will be able to reliably reflow text onto small screens, provide powerful navigation options, transform text appearance, improve search engine functionality, aid in the selection and copying of text, and more.

History

The PDF/UA project began in 2004 as an AIIM Standards Committee. The PDF/UA wiki, operated by AIIM, contains agendas, meeting-minutes and public-access documents pertaining to the development of PDF/UA.

Chaired since 2005 by Duff Johnson, in 2009 AIIM's PDF/UA Committee became the U.S. Committee for ISO/AWI (Accepted Work Item) 14289 with Cherie Ekholm of Microsoft as International Project Leader.

The US Committee continued as the main driver of the standard's development through the WD, CD, DIS and FDIS Phases of ISO standards development, with review, comment and balloting by the member bodies of ISO TC 171.

ISO 14289-1:2012 (PDF/UA) was published in July, 2012. A minor update (ISO 14289-1:2014) was published in December 2014. The document is available directly from the ISO's webstore. [12]

In October 2012 the US Library of Congress added PDF/UA to their list of archivable file formats. [13] The LoC's guidance states that PDF/UA is "...a preferred format for page-oriented content by the Library of Congress."

Adobe Systems, the largest implementer of interactive PDF software, has announced its intention [14] to support PDF/UA.

In December 2014 ISO published ISO 14289-1:2014, a minor revision of the original 2012 document. [15]

In March 2016 AIIM and ANSI published PDF/UA as an American National Standard:. [16]

AIIM's US Committee for PDF/UA has published the following documents in support of PDF/UA:

Ongoing ISO and AIIM Committee Activities

Work on ISO 14289-2 (PDF/UA-2) is ongoing. PDF/UA-2 will be based on PDF 2.0.

Committee Organization & Leadership

AIIM's US Committee for PDF/UA led development of the document from 2004 until 2010, when the draft became an ISO NWI. Both US and ISO Committees maintain their work on AIIM's PDF Standards wiki. [1]

Participation by subject matter experts, software developers and other interested parties is invited and encouraged.

PDF Association Activities

The PDF Association helps promote PDF/UA in a variety of ways.

PDF/UA Competence Center

In 2011 the PDF Association created the PDF/UA Competence Center as a way for vendors to develop educational resources and share experiences regarding implementation of PDF/UA. [20] The Matterhorn Protocol (see below) is a product of the PDF/UA Competence Center.

NVDA goes PDF/UA Project

In 2012 and 2013 the PDF Association helped raise money and awareness for NV Access's NVDA to further development of the world's first PDF/UA conforming screen reader. [21]

The Matterhorn Protocol

In August 2013 the PDF Association's PDF/UA Competence Center published the Matterhorn Protocol, a set of 31 checkpoints and 136 failure conditions to help software developers make it easier for document authors to create fully accessible PDF files and forms. [22]

The PDF/UA Reference Suite

In June 2014 the PDF Association's PDF/UA Competence Center published the first iteration of the PDF/UA Reference Suite, a set of reference-quality documents conforming to PDF/UA-1. [23]

The Tagged PDF Best Practice Guide

In December 2015 the PDF Association's PDF/UA Competence Center unveiled the first public draft of its Tagged PDF Best Practice Guide. [24] Publication is expected by the summer of 2016.

Seminars, Books and Brochures

The PDF Association conducted numerous educational seminars on PDF/UA throughout Europe, North America and Australia in 2012 and 2013. A book, "PDF/UA in a Nutshell", [6] was produced in both English and German. An informational brochure [25] was also produced in both languages.

Related Research Articles

<span class="mw-page-title-main">PDF</span> Portable Document Format, a digital file format

Portable Document Format (PDF), standardized as ISO 32000, is a file format developed by Adobe in 1992 to present documents, including text formatting and images, in a manner independent of application software, hardware, and operating systems. Based on the PostScript language, each PDF file encapsulates a complete description of a fixed-layout flat document, including the text, fonts, vector graphics, raster images and other information needed to display it. PDF has its roots in "The Camelot Project" initiated by Adobe co-founder John Warnock in 1991. PDF was standardized as ISO 32000 in 2008. The last edition as ISO 32000-2:2020 was published in December 2020.

Tag Image File Format or Tagged Image File Format, commonly known by the abbreviations TIFF or TIF, is an image file format for storing raster graphics images, popular among graphic artists, the publishing industry, and photographers. TIFF is widely supported by scanning, faxing, word processing, optical character recognition, image manipulation, desktop publishing, and page-layout applications. The format was created by the Aldus Corporation for use in desktop publishing. It published the latest version 6.0 in 1992, subsequently updated with an Adobe Systems copyright after the latter acquired Aldus in 1994. Several Aldus or Adobe technical notes have been published with minor extensions to the format, and several specifications have been based on TIFF 6.0, including TIFF/EP, TIFF/IT, TIFF-F and TIFF-FX.

A de facto standard is a custom or convention that is commonly used even though its use is not required.

The World Wide Web Consortium (W3C)'s Web Accessibility Initiative (WAI) is an effort to improve the accessibility of the World Wide Web for people with disabilities. People with disabilities encounter difficulties when using computers generally, but also on the Web. Since they often require non-standard devices and browsers, making websites more accessible also benefits a wide range of user agents and devices, including mobile devices, which have limited resources. According to a US government study, 71% of website visitors with disabilities will leave a website that is not accessible.

The Open Document Format for Office Applications (ODF), also known as OpenDocument, standardized as ISO 26300, is an open file format for word processing documents, spreadsheets, presentations and graphics and using ZIP-compressed XML files. It was developed with the aim of providing an open, XML-based file format specification for office applications.

XFA stands for XML Forms Architecture, a family of proprietary XML specifications that was suggested and developed by JetForm to enhance the processing of web forms. It can be also used in PDF files starting with the PDF 1.5 specification. The XFA specification is referenced as an external specification necessary for full application of the ISO 32000-1 specification. The XML Forms Architecture was not standardized as an ISO standard, and has been deprecated in PDF 2.0.

Web accessibility, or eAccessibility, is the inclusive practice of ensuring there are no barriers that prevent interaction with, or access to, websites on the World Wide Web by people with physical disabilities, situational disabilities, and socio-economic restrictions on bandwidth and speed. When sites are correctly designed, developed and edited, more users have equal access to information and functionality.

iText is a library for creating and manipulating PDF files in Java and .NET. It was created in 2000 and written by Bruno Lowagie. The source code was initially distributed as open source under the Mozilla Public License or the GNU Library General Public License open source licenses. However, as of version 5.0.0 and version 4.2.0 it is distributed under the GNU Affero General Public License version 3. A fork of the LGPL/MPL licensed version of iText is currently being actively maintained as the OpenPDF library on GitHub. iText is also available through a proprietary license, distributed by iText Software NV.

Open XML Paper Specification is an open specification for a page description language and a fixed-document format. Microsoft developed it as the XML Paper Specification (XPS). In June 2009, Ecma International adopted it as international standard ECMA-388.

PDF/A is an ISO-standardized version of the Portable Document Format (PDF) specialized for use in the archiving and long-term preservation of electronic documents. PDF/A differs from PDF by prohibiting features unsuitable for long-term archiving, such as font linking and encryption. The ISO requirements for PDF/A file viewers include color management guidelines, support for embedded fonts, and a user interface for reading embedded annotations.

A proprietary file format is a file format of a company, organization, or individual that contains data that is ordered and stored according to a particular encoding-scheme, designed by the company or organization to be secret, such that the decoding and interpretation of this stored data is easily accomplished only with particular software or hardware that the company itself has developed. The specification of the data encoding format is not released, or underlies non-disclosure agreements. A proprietary format can also be a file format whose encoding is in fact published, but is restricted through licences such that only the company itself or licensees may use it. In contrast, a open or free format is a file format that is published and free to be used by everybody.

<span class="mw-page-title-main">Web Content Accessibility Guidelines</span> Web accessibility guidelines

The Web Content Accessibility Guidelines (WCAG) are part of a series of web accessibility guidelines published by the Web Accessibility Initiative (WAI) of the World Wide Web Consortium (W3C), the main international standards organization for the Internet. They are a set of recommendations for making Web content more accessible, primarily for people with disabilities—but also for all user agents, including highly limited devices, such as mobile phones. WCAG 2.0 was published in December 2008 and became an ISO standard, ISO/IEC 40500:2012 in October 2012. WCAG 2.2 became a W3C Recommendation on 5 October 2023.

GeoPDF is a line of map and imagery products created by TerraGo software applications. GeoPDF products use geospatial PDF as a container for maps, imagery, and other data used to deliver an enhanced user experience in TerraGo applications. However, GeoPDF products conform to published specifications including both the OGC best practice for PDF georegistration as well as Adobe's proposed geospatial extensions to ISO 32000, making them readable by applications such as Adobe Acrobat, Adobe Reader, Avenza PDF Maps, Global Mapper, and others.

PDF/X is a subset of the ISO standard for PDF. The purpose of PDF/X is to facilitate graphics exchange, and it therefore has a series of printing-related requirements which do not apply to standard PDF files. For example, in PDF/X-1a all fonts need to be embedded and all images need to be CMYK or spot colors. PDF/X-3 accepts calibrated RGB and CIELAB colors, while retaining most of the other restrictions of PDF/X-1a.

The following is a comparison of e-book formats used to create and publish e-books.

ISO 24517-1:2008 is an ISO Standard published in 2008.

Geospatial PDF is a set of geospatial extensions to the Portable Document Format (PDF) 1.7 specification to include information that relates a region in the document page to a region in physical space — called georeferencing. A geospatial PDF can contain geometry such as points, lines, and polygons. These, for example, could represent building locations, road networks and city boundaries, respectively. The georeferencing metadata for geospatial PDF is most commonly encoded in one of two ways: the OGC best practice; and as Adobe's proposed geospatial extensions to ISO 32000. The specifications also allow geometry to have attributes, such as a name or identifying type.

PDF/VT is an international standard published by ISO in August 2010 as ISO 16612-2. It defines the use of PDF as an exchange format optimized for variable and transactional printing. Built on top of PDF/X-4, it is the first variable-data printing (VDP) format which ensures modern International Color Consortium-based (ICC) color management through the use of ICC Output Intents. It adds the notion of encapsulated groups of graphic objects to support optimized efficient processing for repeating text, graphic or image content. Introducing the concept of document part metadata (DPM), it enables reliable and dynamic management of pages for High Volume Transactional Output (HVTO) print data, like record selection or postage optimization based on metadata.

The Portable Document Format (PDF) was created by Adobe Systems, introduced at the Windows and OS/2 Conference in January 1993 and remained a proprietary format until it was released as an open standard in 2008. Since then, it has been under the control of an International Organization for Standardization (ISO) committee of industry experts.

References

  1. 1 2 "PDF Standards - PDF/UA". pdf.editme.com. Archived from the original on 5 November 2017.
  2. ↑ "What is PDF/UA all about, anyway? « Adobe Accessibility".
  3. ↑ "PDFlib whitepaper: "A Technical Introduction to PDF/UA (PDF)" (PDF).
  4. ↑ "Board Proposes Updated ICT Accessibility Requirements - United States Access Board". www.access-board.gov.
  5. ↑ "A New Standard for PDF Accessibility: PDF/UA « Adobe Accessibility".
  6. 1 2 "PDF/UA in a Nutshell". June 16, 2013.
  7. ↑ "The PDF/UA Standard". www.pdflib.com.
  8. ↑ "PDF Techniques | Techniques for WCAG 2.0". www.w3.org.
  9. ↑ WCAG 2.0 and PDF/UA - your questions answered
  10. ↑ "PDF/UA-1:2014 now published". December 22, 2014.
  11. ↑ "ISO 14289-1:2012". ISO.
  12. ↑ ISO 14289 available from ISO.org
  13. ↑ "PDF/UA-1, PDF Enhancement for Accessibility, Use of ISO 32000-1". www.loc.gov. March 29, 2019.
  14. ↑ "WCAG 2.0 and PDF/UA « Adobe Accessibility".
  15. ↑ "ISO 14289-1:2014". ISO.
  16. ↑ "Sorry, the requested URL was not found on this server". www.aiim.org.
  17. ↑ "Achieving WCAG 2.0". www.aiim.org.
  18. ↑ "Technical Implementation Guide PDF/UA". www.aiim.org.
  19. ↑ "Technical Implementation Guide PDF/UA and ISO 32000-1". www.aiim.org.
  20. ↑ "PDF/UA Competence Center".
  21. ↑ "NVDA goes PDF/UA! The PDF Association Steps Up to Fund Development of the World's First PDF/UA Conforming Screen Reader".
  22. ↑ "The Matterhorn Protocol". PDF Association. Retrieved 2014-06-18.
  23. ↑ "The PDF/UA Reference Suite". PDF Association. Retrieved 2014-06-19.
  24. ↑ PDF/UA Competence Center Tagged PDF Best Practice Guide
  25. ↑ "PDF Association flyers (English)". 18 June 2021.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.