In January 2017, the U.S. Access Board issued the Information and Communication Technology (ICT) Standards and Guidelines, updating its existing Electronic and Information Technology Accessibility Standards under Section 508 of the Rehabilitation Act of 1973, (“508 Standards”), and the Telecommunications Act Accessibility Guidelines under Section 255 of the Communications Act of 1934 (“255 Guidelines”). These Standards are now in effect as of January 18, 2018.

PDF/UA is needed because while the PDF specification creates accessibility mechanisms it fails to set clear rules for actually creating (or delivering) reliably accessible PDF content.

“UA” stands for Universal Accessibility; PDF/UA designation certifies that documents are compliant with ISO Standard 14289, the new international standard for Accessible PDFs. There are approximately 25 million individuals in the US, 1 million individuals in Canada and over 30 million individuals in the EU that have difficulty reading bills, statements and other customer communications. A document that has been produced in the PDF/UA format using best practices will guide customers’ assistive technology to present that document in the most accessible way possible.

In a Nutshell:

A PDF/UA document is a PDF file that contains specific content in it’s infrastructure to make its content as accessible as possible to users that require assistance to access the content, primarily using “screen readers” that allow a sight-impaired user to navigate a document as it is read aloud. The main points:

  • Content is tagged. The tags used describe what the content is, for example a heading, and the order of that content within the document – this guides the screen reader and facilitates navigation through the document.
  • Graphical elements have a text description so that a user can know what that element is.
  • Tables have tags for their column headings and row headings so that the user can know what the values within the table represent.
  • Fonts must be embedded
  • The language of the document is specified

These are just the basics. A protocol has been developed, the Matterhorn Protocol, that defines 136 attributes a PDF/UA document will contain. Like all PDFs, it is a document that will print and be viewed electronically uniformly across all platforms. It also contains metadata within the tags that may make such PDFs more suitable for archive and retrieval purposes and can be produced in such a way that it also conforms to the PDF/A standard for long term preservation of electronic documents.

The importance of PDF/UA documents is that they conform to the definitive standard for Accessible PDFs that the ISO (International Organization for Standardization) has published based on efforts of a global consortium of technology experts spanning almost a decade. This is a concise, prescriptive guide to using the tagging and other content storage and organization technology in PDFs to document the hierarchy and structure specific to the contents for each document type. With these tags, a PDF/UA document enables your customers’ assistive technology to present the contents in a logical order that enables comprehension, making the content both accessible and usable

A bit of history:

Back in 2000, Adobe added the capability to add “tags” within PDF files. To use an uncommon word for a moment, tags add “semantic” meaning to content within a PDF and tells us what that content is. For example, a tag might tell us that content is an image or a table. Another example is to have a heading tag applied to content within the PDF, identifying headings and their relative importance (“Heading 1” is more important than “Heading 2”). This introduction of tags is important because it started to lay the groundwork for making PDFs accessible. In 2008, Adobe’s Reference 1.7 version of PDF became a Standard (ISO 32000-1:2008). Adobe handed the ongoing management and enhancement of PDF to subject-matter expert committees around the world through the International Organization for Standardization (ISO).
PDF/UA and regulatory compliance

There are many regulations that specify what your organization’s obligations are with regard to meeting the needs of people with disabilities. An obvious example is handicapped parking spaces. In the United States these are often called ADA parking, where ADA stands for ‘Americans with Disabilities Act.’ Other examples include ramps for wheelchairs, push buttons that automatically open a door, etc. All of these are required by law. PDF/UA documents meet or exceed the regulations set down in Section 508 of the Rehabilitation Act

PDF/UA is one of many ways your organization can provide accessible electronic documents to your customers and help you meet regulatory obligations, while providing the best possible experience.

Added benefits of PDF/UA:

  • A PDF/UA file can also be a PDF/A file, offering a single approach to address both your long-term archiving requirements as well as accessible PDF requirements.
  • A PDF/UA file, due to its content tagging, makes the user experience on mobile devices much better due to text reflow as an alternative to zooming in on content in order to read it
  • A PDF/UA file can make content re-use easier due to the fact that the content is tagged. For example, copy & paste or extracting to HTML is more easily achieved.
  • A PDF/UA file can provide better search results. If your archive or search tool can utilize PDF tags, the ability to find what you are looking for can be based on the complete set of actual PDF document content.

Details of PDF/UA

All PDF/UA documents must be tagged PDF. Tags must be semantically appropriate (that is, you can’t just mark everything <p> and be done), and in logical reading order. Artifacts (sometimes referred to as “Background” in Acrobat) must not be tagged. If a PDF does anything non-standard with its tags, those tags have to be remapped to standard PDF tags. Standard tags can’t be overridden.

Content can’t flicker, blink or flash, and it can’t be conveyed solely by color, contrast, formatting,  layout or sound. Image-only PDFs may be created, but their content must also be tagged.

The document must have a title, and it must be displayed in the title bar.

Text must be Unicode. The document’s language, and any changes in language, must be declared.

Graphics must be marked up with the Figure tag, and must have alt text, unless it’s presentational, in which case it’s an Artifact. Groups of images that represent one thought are to be tagged as a single Figure. Captions that go with figures must be tagged as such.

Headings must be nested sequentially (e.g., H1-H2-H3 is acceptable, but H1-H3 is not). Headings can go as deep as necessary (e.g., H1041 is valid, if you’ve used the first 1040 levels). Generic “H” headings are acceptable, but can’t be used interchangeably with numbered headings.

Tables should have headers (“TH” tags) with a Scope attribute.

Lists must be marked up appropriately.

Math equations must be in a Formula tag, with alt text.

Page headers and footers must be marked up as Pagination artifacts, so they’re not read out repeatedly.

Footnotes and endnotes must be marked up with the Note tag.

All optional content configuration dictionaries (a PDF feature which allows content to be hidden conditionally) must be named.

Any embedded files must also be accessible.

Article threads (which allow multicolumn layouts across pages) must retain proper reading order.

Digital signature form fields must be laid out accessibly.

Non-interactive forms have to be tagged with PDF “PrintField” attributes so they will appear as read-only form fields to AT.

Static XFA-based forms are allowed. Dynamic XFA forms are not.

Secured documents must allow AT access.

Documents should have outlines that reflect the reading order and nav hierarchy.

Visible annotations must be represented in the right place in the reading order.

Tab order must be defined.

Links must be tagged, and contain an alternate description.

Metadata tags must be properly set for embedded media.

Actions (i.e., scripting) are allowed. Changes in content or focus must be announced to AT, and cannot set time limits on individual keystrokes.


Please contact us for more information on making your documents compliant with Section 508 and PDF/UA.

Matterhorn Protocol: http://www.pdfa.org/wp-content/uploads/2014/06/MatterhornProtocol_1-02.pdf provides 136 criteria for PDF/UA compliance, of which 47 require human judgment.