Conflicts when creating accessible PDF documents (3/3)

Accessibility and PDF/UA

PDF and accessibility – a broad field that also brings potential for conflict.

Whether in the analogue or digital world, the topic of accessibility is a complex one and can be viewed from many different angles. An environment is considered barrier-free if it has been designed in such a way that it can be used by all people equally (without assistance) without barriers/hurdles, i.e. also by people with impairments of any kind.

In the digital world and in relation to the PDF format, the question “Can PDF documents really be accessible?” can be answered with a clear “yes” if you have a certain basic knowledge and take a few stumbling blocks into account when creating and checking documents.

The persistent rumour that there are no accessible PDFs can safely be considered outdated, although it has to be said that the topic has unfortunately been treated stepmotherly for too long and there is still a need to catch up. Accessibility has to be considered in many different ways and the extent to which a document is really accessible can only be proven 100% in practice by a blind person trying to read the PDF document. This means that a 100% validation of whether a PDF document is accessible can ultimately only be done audiovisually. It must be said that the PDF/UA format (for Universal Accessibility) does not automatically mean 100% accessibility, it is merely an industry standard and one should have additional background knowledge so that these documents are also created without any problems.

General information on PDF and accessibility: What conflicts exist and why?

Conflicts on the topic of accessibility can arise, among other things, from the fact that PDF documents, by their very nature, are intended to leave the appearance of a document unchanged. The PDF format, which originally came from PostScript printing technology and not from structured document formats such as XML, was always intended to remain true to the original as a document and thus focused more on the print-like, visual impression than on the meaning and structure of the content. These in turn are important for people for whom the visual impression is lost when they have to read the document with a screen reader.

For this reason, there are always barriers for blind people who depend on the content being structured by certain markings. For the output and preparation of the document content by screen readers, tags must be inserted when the PDF document is created. This refers to standard elements such as headings or paragraphs. These are then used for orientation. (You could learn more about this in Part 2 of this series).

Common problem: Secured PDF documents

A quite common problem is also that PDF documents cannot always be barrier-free. This is always the case if the document consists of a raster graphic, has several columns, contains an unknown character set or the text is simply copy-protected. Such documents cannot be read by screen readers.

Conflicts when checking for accessibility

Additional difficulties can arise when validating accessible PDF documents. It can happen during the check that files are wrongly classified as accessible. Therefore, it is essential that you do not rely solely on a purely automatic check.

Important points to consider during the check as well:

  • If the otherwise useful reflow function is used, you should check for display errors
  • Tags that were sensibly used for structuring must be smeantically and syntactically correct
  • Also note when using the Matterhorn protocol or PAC tests: Some items need to be looked at with human judgement, it is not always sufficient to check them automatically
  • There may also be requirements included in the EN 301549 standard (European Directive/Digital Accessibility Requirements) that are not covered by the PDF/UA standard, so it is also recommended to pay additional attention to these.

What specifications must be observed for PDF validation?

One has to consider different aspects when checking for accessibility. It is a bit of a challenge to find the right balance here and to meet all requirements. In addition to aspects of general usability, one must take both the PDF/UA standard and the requirements of the WCAG as a starting point and also have the EN 301549 standard and the ISO 14289 standard in mind. This means that the creators of accessible PDF documents must have a basic knowledge of accessibility, digitisation and usability. Unfortunately, this is not always the case, or only in areas where web design is clearly involved. There is clearly a need to catch up and potential for conflict here. One can state in this context: The more people are trained in accessibility, the more can be implemented in PDF creation.

You are always on the safe side if you observe the international standard (ISO 14289) and safeguard it with the so-called PAC 2021 test. The current PAC Test (PDF Accessibility Checker) of the PDF/UA Foundation is an important tool for checking accessibility. This ensures PDF/UA conformity on the one hand and WCAG conformity on the other. However, an additional visual check/test with a screen reader is still important, because here too it is primarily a matter of the machine-checkable criteria.

Conclusion: Accessible PDF documents

One thing is certain: many people benefit from accessible documents. Namely, all non-native speakers or illiterate or partially illiterate people, who are more numerous than one would think. They could, for example, use the Read Out Loud Text-to-Speech tool by Adobe Reader for accessible PDF documents.

The myth that PDF documents are not accessible is not true, and unfortunately this is still too little known. But the fact is: you can make almost any PDF file at least as easily accessible as a website. PDF documents are in any case better than their reputation. Tagged PDF, or later the PDF/UA standard, has been under development for many years (PDF/UA-2 was developed based on PDF 2.0) and there is clearly a concern that PDFs can be made accessible/barrier-free in this form. Critically, one could add that the possibility of accessibility in PDF documents is still too little used or has also been developed too little and too slowly.

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