About the contributor
Duff Johnson

A veteran of the electronic document space, Duff Johnson is an independent consultant. He is Executive Director of the PDF Association and ISO Project co-Leader (and US TAG chair) for ISO 32000 and ISO 14289.
More contributions
PDF Days Europe underscores the importance of PDF as a key component of business processes

2017 marks a record number of attendees / Experts shared fully-grounded wisdom on PDF standards across the two-day event Berlin. With over 200 attendees, this year’s PDF Days Europe in Berlin was a significant success with the largest attendance of any …

Slides and video recordings of the PDF Days Europe 2017

About 35 informative sessions across a wide range of topics, including the next-generation PDF project. Within the video frames you can use the red “play” button to get a short impression of the talk or can enjoy the high resolution version by clicking …

PDF Days Europe 2017 hits the target!

With more than 200 participants, this year’s PDF Days Europe was the largest to-date. Early feedback from attendees makes clear that it was also a great success.

PDF/X in a Nutshell

PDF for printing – The ISO standard PDF/X was the  first ISO standard based on PDF technology. A subset of the PDF specification, PDF/X was designed to constrain PDF  files in order to cater to specific use-cases in the print industry. Content Introduc …

Final agenda of the PDF Europe 2017 available as download

More than 150 attendees have registered for the PDF Days Europe 2017 so far!

The Value of Tagged PDF


PDF was originally intended to serve as electronic paper; a properly rendered page irrespective of software or operating system.  Pages, however, aren’t just for reading. Since people like to add notes, draw lines and fill forms, Adobe Systems, the inventors of PDF, decided to cater to these uses as well. PDF rapidly accumulated new features beyond faithfulness to the rendered page – it began to mirror the interactive capabilities of real paper.

The first generation of interactive PDF features consisted of annotations of various types. Some allowed users to add text, others allowed users to draw lines and boxes onto the page. Still others go beyond the paradigm of the page, making it possible to add hyperlinks,  audio and movies to PDF.

The second generation of interactive PDF brought the ability to deploy a PDF’s content outside the page-based world.

Tagged PDF provides the means to effectively deploy a final-form document to a mobile device. It’s the same means by which PDF files may be made accessible to users who requires Assistive Technology (AT) to read.

One of the primary motivations for tagged PDF was to achieve compliance with regulations that require electronic documents to be accessible to users with disabilities, but implementers can leverage tagged PDF to accomplish or enhance a wide range of end user activities.

The following table indicates the utlity of untagged vs. tagged PDF content.

Untagged Content Tagged Content
No semantic types or ordering; content is ordered solely for rendering purposes Semantic type and order is determined, content may be reused accordingly
Search engines cannot reliably access words and phrases Search engines get reliable access to content.
No reliable means of reflowing page content onto smaller devices Includes information necessary for reflow
“Real” content and “artifacts” aren’t distinguished Consuming software can choose to utilize or ignore artifacts
Content copying and extraction is unreliable Content may be extracted with confidence
Not eligible for PDF/A conformance level A May conform with PDF/A conformance level A
Cannot comply with WCAG 2.0 or Section 508 May comply with WCAG 2.0, Section 508 and other accessibility regulations
Inaccessible to disabled users Accessible to those with PDF-aware Assistive Technology

Tags: Section 508, WCAG 2.0, assistive technology, mobile, tags
Categories: PDF, PDF/UA