Substantial effort has been made to ensure that the Web-client is accessible to people with disabilities. Although no special configuration is needed to make the Web-client's accessibility features available, merchants still have a responsibility in producing documents that comply with accessibility guidelines.

XML documents

There are a couple of key points to have in mind when producing XML documents with accessibility principles in mind. Note that this list is by no means exhaustive.

Document dimensions

Optimally the document should not expand beyond the available width. Creating broad elements that expands beyond the Web-client's available width is not recommended and is considered bad practice.

An example of such an element is a table with a large number of columns. As a rule of thumb the document should not produce a horizontal scrollbar when the available width is 396 pixels.

Document structure and semantics

Assistive technologies will operate optimally on documents that have sound structure and semantics.

Think in terms of semantics when choosing relevant tags.
Make use of heading tags – ideally it should be possible to comprise a table of contents from the document's headings.
Images should always have a text alternative that conveys its contents.

Tables

Tables are particularly difficult to communicate through assistive technologies, e.g. screen readers. Interpreting a cell's contents depends on a coordinated understanding of its row and column context. With this in mind there are several key points to consider when producing tables in XML documents.

Tables should be used for data – not for layout purposes. If a table is used for presentation it should have an appropriate role description.
Always make use of headers for each column and row.
Use the simplest table configuration possible.
Make correct use of table structure and semantics.
Consider converting table to other structures, e.g. a list with label and value pairs, ensuring the content is still easily understandable.

PDF documents

The Web-client in its 2.1 version presents PDF documents in the form of PNG-images. In order for assistive technologies to operate on such documents the Web-client allows for the user to download and open the document in a preferred PDF reader client (see Figure 3).

The 2.0 Web-client only presents a download link to the PDF document. It does not support display of the document within the Web-client.

In order to provide a basis for proper support for universal accessibility, merchants should produce documents that comply to the PDF/UA (PDF/Universal Accessibility) and PDF/A specifications. PDF/UA provides definitive terms and requirements for accessibility in PDF documents.For those equipped with appropriate software, conformance with PDF/UA ensures that the document is accessible.