Posts in Category "PDF"

May 7, 2012

WCAG 2.0 and PDF/UA

Harmonization of accessibility standards is a primary goal for Adobe which is why for many years Adobe has worked on the W3C Web Content Accessibility Guidelines (WCAG) working group – our participation was driven by a desire to help define a WCAG 2.0 standard which would be useful for web content that Adobe tools are involved with the authoring or display of, including PDF, Flash, HTML, and more. There is great benefit for developers, authors, and end users when there is an agreed on standard for what constitutes an accessible experience, and it is encouraging to see that WCAG 2.0 is regarded as the primary standard for web accessibility and is referenced by national governments around the world. However, there is more to achieving accessibility than the normative text of WCAG 2.0.

In 2004, Adobe and AIIM started the PDF/UA (Universal Accessibility) activity with the intent of producing standards specific to PDF authoring and presentation which ensure that conforming PDF (ISO 32000-1) files are accessible and usable to all, including users who rely on assistive technology. Today, PDF/UA is ISO 14289-1, a “Final Draft International Standard (FDIS)”, expected to be published later in 2012.

We’ve received many questions about the relationship between PDF/UA and WCAG 2.0. WCAG 2.0 was developed as a technology-independent standard and provides individual (normative) success criteria for accessibility which are general enough to apply across technologies. The W3C’s WCAG working group also provides a growing collection of advisory (non-normative) techniques to offer technology-specific guidance, including a growing set of techniques for HTML, CSS, Scripting, PDF, Flash, and more. Beyond these techniques, developers need to conduct additional research to ensure that the content or applications they create meet the WCAG 2.0 success criteria – for example, a Java developer looking to offer a compliant applet will not find techniques on the W3C site at this time, but may be able to meet WCAG 2.0 if they correctly follow guidance provided elsewhere and evaluate the resulting applet against the WCAG success criteria.

PDF developers need this type of clarity on how to meet WCAG 2.0, and the PDF techniques, while useful, do not presently represent a complete set which encompass all technical requirements for accessibility in all PDF documents. This is where PDF/UA provides help. PDF/UA provides normative technical specifications for the use of the PDF format, defining proper structure and syntax to enable reliable access. This includes identification of necessary tagging structures, how to specify alternative text for images, how to ensure correct Unicode mappings for character glyphs, and many other file, page and object-level specifications, as well as how Reader applications and assistive technologies can fully process PDF/UA conforming files to maximize accessibility.

PDF/UA defines the technical specifications to enable PDF documents to meet WCAG 2.0, but WCAG 2.0 has additional requirements which require an author’s attention. The areas where WCAG 2.0 has additional requirements include time-based media (guideline 1.2), scripting and actions (e.g. success criteria 3.2.1 and 3.2.2), and certain types of content (e.g. success criteria 2.4.4). For these and other additional requirements, the W3C’s technique documents (both general and PDF-specific techniques) provide guidance for authors interested in complying with WCAG 2.0.

PDF/UA clarifies and simplifies the PDF-specific technical requirements to meet WCAG 2.0. Adobe fully supports PDF/UA and intends to use and promote it in our PDF authoring tools. Adobe also plans to support the conforming Reader requirements, which are part of PDF/UA. Authors using Adobe tools such as Adobe Acrobat will be enabled to support PDF/UA as a first and major step toward compliance with WCAG 2.0.

9:00 AM Permalink
January 3, 2012

WCAG 2.0 Techniques for PDF

Authors looking for additional guidance on how to meet the W3C WCAG 2.0 for PDF documents can now look to the W3C techniques repository for additional guidance. Techniques for PDF authored over the past two years since the release of the last update to the WCAG techniques (which included techniques for Flash) are now part of the larger collection of techniques. View the full set of WCAG 2.0 techniques or view PDF techniques on their own.

These techniques provide a clear path for demonstrating that a PDF document can meet the most current accessibility standard from the W3C.

As with the Flash techniques for WCAG 2.0 and techniques for all other technologies, the PDF techniques are presented as examples which the WCAG Working Group viewed as sufficient to meet WCAG 2.0 success criteria, not as the only way to meet any given success criteria. Authors may discover a new way to address a success criteria, in a way not yet covered in the existing techniques, and be able to demonstrate why it is sufficient. The techniques offer a collection of strategies that have been reviewed by the working group, but the techniques collections for all technologies are works in progress as there are always additional ways to address success criteria.

The table below provides a listing of the WCAG level A and AA success criteria and the PDF-specific and General techniques that authors can employ to meet success criteria. It is worth noting that not all success criteria for WCAG 2.0 have technology-specific techniques. For example 1.3.3 (Sensory characteristics) has only general techniques, and in this case and similar ones I reference the relevant general techniques section. In some cases there are relevant general techniques as well as PDF-specific techniques and for these both are linked.

Update: I neglected to acknowledge the hard work of Mary Utt from The Paciello Group on the PDF techniques initially, but Mary was a tremendous help in moving this work forward and I offer many thanks. Many people on the WCAG working group also worked very hard to help make these techniques reach this final stage. Thanks to all!

Please send general comments, comments or questions on the techniques, or suggestions for new techniques.

WCAG 2.0 Success Criteria and Applicable Techniques for PDF
Success Criteria Level Techniques
1.1.1 Non-text Content A
1.2.1 Audio-only and Video-only (Prerecorded) A
1.2.2 Captions (Prerecorded) A
1.2.3 Audio Description or Media Alternative (Prerecorded) A
1.2.4 Captions (Live) AA
1.2.5 Audio Description (Prerecorded) AA
1.3.1 Info and Relationships A
1.3.2 Meaningful Sequence A
1.3.3 Sensory Characteristics A
1.4.1 Use of Color A
1.4.2 Audio Control A
1.4.3 Contrast (Minimum) AA
1.4.4 Resize text AA
1.4.5 Images of text AA
2.1.1 Keyboard A
2.1.2 No Keyboard Trap A
2.2.1 Timing Adjustable A
2.2.2 Pause, Stop, Hide A
2.3.1 Three Flashes or Below Threshold A
2.4.1 Bypass Blocks A
2.4.2 Page Titled A
2.4.3 Focus Order A
2.4.4 Link Purpose (In Context) A
2.4.5 Multiple ways AA
2.4.6 Headings and Labels AA
2.4.7 Focus Visible AA
3.1.1 Language of page A
3.1.2 Language of parts AA
3.2.1 On Focus A
3.2.2 On Input A
3.2.3 Consistent Navigation AA
3.2.4 Consistent Identification AA
3.3.1 Error Identification A
3.3.2 Labels or Instructions A
3.3.3 Error Suggestion AA
3.3.4 Error Prevention (Legal, Financial, Data) AA
4.1.1 Parsing A
  • Not Applicable: PDF is not implemented using markup languages
4.1.2 Name, Role, Value A
10:49 PM Permalink
June 29, 2011

InDesign 5.5 Accessibility Webinar

Just a heads up that Noha Edell from Adobe is offering a webinar on InDesign CS5.5 accessibility, this Friday, July 1 at 3pm Eastern/12pm Pacific.

The InDesign team has made substantial improvements in accessibility support. Authors now have complete control over generated reading order, can provide tables and lists that are tagged correctly without any need for repair in Acrobat, and have more sophisticated support for alternative text for images.

This webinar is a must-see for anyone who uses InDesign for the creation of PDF documents that need to be accessible. The webinar is Friday, July 1, at 12 p.m. PT at

More information about the event is available at

1:56 PM Permalink
March 11, 2011

Adobe at CSUN 2011 Conference

The California State University at Northridge’s Conference on Disability is going on March 16-18, 2011, and Adobe is offering a number of sessions that we hope people will find interesting and informative, as well as offering opportunities to talk directly to Adobe’s accessibility team and product team members.

The event will feature several sessions and events that I want to provide some details for. Here’s our schedule of events:

Wednesday, March 16

Thursday, March 17

Friday, March 18

The following is not an Adobe session, but it is introducing a valuable resource in the form of a course on accessible Flash development, developed jointly by the Department of Veterans Affairs and SSB BART Group.

Adobe will have several people at CSUN and will be attending the TweetUp as well as being available to talk between or after sessions. Please come introduce yourself and ask questions and share your thoughts.

4:25 PM Permalink
February 18, 2011

PDF Accessibility Training for Australian Government

Adobe is running a series of training in Australia the first week of March to help Australian Government employees understand how to create accessible PDF documents. The trainings are being held in Canberra at the National Museum of Australia, but will be recorded and made available online after the sessions (probably with a 1-2 week delay in order to have the recordings captioned and posted). We are running these sessions in conjunction with the Australian Government Information Management Office (AGIMO).

I’m delivering two different presentations (twice each):

  • PDF Accessibility for Everyone – suitable for a wide range of user knowledge of accessibility, focusing on common authoring pathways
  • PDF Accessibility for Techo’s – an advanced session for people with good knowledge of accessibility

More information about the sessions, and registration for attendance, is now available.

I’m looking forward to these sessions and helping people understand how to create PDF documents that meet WCAG 2.0 and are easily used by people with disabilities.

4:08 PM Permalink
November 30, 2010

Quick Thoughts On Canadian Legal Ruling

There was an important ruling today on accessibility from the Canadian Federal Court that is worth a read.

A blind woman filed suit against the government of Canada stating that the government “violated her rights under section 15(1) of the Canadian Charter of Rights and Freedoms, Part I of the Constitution Act, 1982”. In short the findings of the court were that many web sites for the Canadian government are not meeting the Common Look and Feel standard (CLF). The Court found that the government should update the CLF standard to utilize WCAG 2.0 instead of WCAG 1.0 and that there is sufficient evidence of compliance problems that need to be addressed that the Court found that the applicant was discriminated against due to the need to access information and apply for employment via these websites. The Court is allowing the government 15 months to come into compliance.

There are a couple of points raised in the ruling and in a Globe and Mail online article (Court orders Ottawa to make websites accessible to blind) that I would like to clarify. The points are as follows:

  • From the ruling: “The applicant testified that in June 2007 she attempted to access information on the consumer price index and unemployment rate from the Statistics Canada website. She stated that actual statistics were, however, only available in “pdf” format, which is not accessible to screen reader technology.”
  • From the ruling: [reported by a witness for the applicant] “…for example, “flash” is a technology that cannot be read by many screen readers. If a website uses “flash” technology, the user will not be able to access that content…”
  • From the Globe and Mail article: “Many blind people use screen readers, computer software that translates electronic text into audio. But the readers aren’t foolproof — for one thing, most can’t decipher PDF files, a format often used to publish documents online.”

None of these is accurate. Even in 2007, most screen readers could read PDF and Flash capably. In fact, the screen reader used by the applicant was capable of reading both PDF and Flash. The points above indicate that most screen readers can’t read PDF or Flash, but it is more accurate to say that most can, including JAWS, Window-Eyes, NVDA, and others. Adobe provides a “read out loud” feature in Adobe Reader that provides basic access to PDF documents, but most users who are blind will depend on a more full-featured assistive technology.

This is not to suggest that the applicant didn’t encounter challenges, she clearly did. Authors of HTML web pages, as well as authors of PDF documents and Flash content need to make sure that they follow accessibility standards, and if authors don’t, users suffer.

We have techniques available for complying with WCAG 2.0 when authoring Flash, HTML, and techniques for PDF are in the works (there are training resources available for PDF at Adobe’s accessibility site in the meantime). The information that authors need is available, this ruling will undoubtedly stimulate an increased interest in these sources of information.

Adobe is committed to helping authors comply with accessibility requirements, whether using HTML, PDF, or Flash. Here’s a few links to relevant information:

5:09 AM Permalink
November 19, 2010

Reader X, Accessibility, and Security Sandboxing

Yesterday Reader X was released and with it a new feature for security sandboxing. I want to alert assistive technology users to some implications of this feature, as they may be affected if they are using Windows XP.

Sandboxing works without issue for assistive technology users with Windows Vista or Windows 7. Your version of Reader will install with Protected Mode enabled and you don’t need to do anything different to read or interact with PDF documents.

Windows XP users who use assistive technology have a little different situation. When one of these users opens a PDF file they will get an alert that indicates the following:

“Adobe Reader has detected that you may be using Assistive Technology on your computer. While using Adobe Reader with Protected Mode enabled on Windows XP operating systems, some Assistive Technologies may not be able to read some document content. If you do encounter problems, turning off Protected Mode may help. This can be done by choosing Edit > Preferences > General and unchecking Enable Protected Mode at startup.”

Screen shot of alert that appears when an XP user opens a PDF file while assistive technology is running

What this means is that some assistive technologies are not able to navigate the security sandbox. So, as an assistive technology user, you should first check to see if you are able to access PDF content with your AT – JAWS and Window-Eyes users will need to disable Protected mode in the Reader preferences. There are many assistive technologies and many possible system configurations, so we encourage you to try for yourself. For an accessible PDF file to try, here is a simple test PDF file. Feel free to post your results as comments.

Update: This post initially indicated that Window-Eyes 7.2 was able to read in protected mode, but I received incorrect information on this point and was corrected by contacts at GW-Micro. The key issue is that the sandbox blocks COM interfaces, which includes current accessibility APIs, so it does make sense that Window-Eyes doesn’t work within Protected mode on XP.

10:25 PM Permalink
August 13, 2010

New InDesign Accessibility Video

Accessibility in PDF documents exported from InDesign is an are that many InDesign users are increasingly interested in. In response, we’ve worked with the Adobe Government team and Michael Murphy, Adobe Certified Expert, to offer a video that demonstrates InDesign accessibility best practices in action.

View the video (with closed captioning): Preparing InDesign Files for Accessibility

4:33 AM Permalink
July 7, 2010

Linux Foundation Delivers New Licensing for IAccessible2

Today the Linux Foundation announced that it was releasing IAccessible2 with new licensing terms.  IA2 is now available with a BSD license.  You can read about this change as well as the additional tools available at  This is an important change as Adobe works to integrate IA2 into a future version of Adobe Acrobat and Reader, as well as the Flash Player and AIR.

4:15 AM Permalink
April 5, 2010

AFB Consulting Webinar on PDF and Assistive Technologies

AFB Consulting and Adobe worked together to create a session that shares information about how users of assistive technologies can get the most out of PDF files that they interact with.
The session is targeted to users of assistive technologies, particularly screen reader users, and demonstrates techniques to use to access PDF using assistive technology. Topics to be covered include different types of PDFs, using Adobe Reader’s built-in accessibility features, and navigating PDF documents.
The webinar presentation document and demo files are available and will help users try techniques demonstrated by the presenters.
The recording of the session is available. The session is now also available as an mp3 file.

3:55 PM Permalink