Editor’s Note: This article is part of the Accessible PDF Learning Center
Ensuring PDFs are compliant with Section 508 means enabling content for use by devices that suit the needs of a wide variety of disabled users.
It’s not obvious how these requirements apply to PDF files. Here’s a PDF-specific guide to the Section 508 regulations, as adapted from § 1194.22 Web-based intranet and internet information and applications on the Section508.gov website.
(a) ‘A text equivalent for every non-text element shall be provided…’
PDF Translation: Must provide alternate text for every graphic image included in the PDF.
(b) ‘Equivalent[s] for any multimedia presentation…’
PDF Translation: Not applicable for the vast majority of documents., but if you use multilmedia, you’ll need alternate text.
(c) ‘…all information conveyed with color is also available without color…’
PDF Translation: May require re-design of PDFs created from electronic source.
(d) ‘Documents shall be organized so they are readable without requiring an associated style sheet.’
PDF Translation: Treat low-contrast text (shaded areas) as image [see paragraph (a)], or remove shading.
(e) ‘…server-side image-maps.’
PDF Translation: Not Applicable.
(f) Client-side image maps…’
PDF Translation: Applies if the PDF includes hyperlinks.
(g) ‘Row and column headers shall be identified for data tables.’
PDF Translation: Comply via Tags or JavaScript
(h) ‘Markup shall be used … for data tables that have two or more logical levels of row or column headers.’
PDF Translation: Comply via Tags or JavaScript.
(i) ‘Frames shall be titled…’
PDF Translation: Not Applicable.
(j) ‘Pages shall be designed to avoid causing the screen to flicker…’
PDF Translation: Not Applicable.
(k) ‘A text-only page…shall be provided… when compliance cannot be accomplished in any other way.’
PDF Translation: An ‘escape’ clause of sorts for pages with extremely complex content; best avoided.
(l) ‘When pages utilize scripting languages…’
PDF Translation: This is significant for PDFs containing JavaScript, notably when the JavaScript interacts with page-content or performs actions on buttons, fields and the like in order to deliver information to the user.
(m) ‘…page[s] must provide a link to a plug-in or applet that complies with §1194.21(a) through (l).’
PDF Translation: Pages containing links to PDF files must include a link to the Adobe Reader installer.
(n) ‘… electronic forms … shall allow people using assistive technology to access the … functionality required for completion and submission…’
PDF Translation: PDF forms must be tab-ordered correctly, all fields should be properly labeled and field-values must be made explicit in terms of their meaning. If calculations or scripts are operating, providing feedback or other information, such information must be made available to assistive-technology users.
(o) ‘A method shall be provided that permits users to skip repetitive navigation links.’
PDF Translation: This almost never occurs in PDF, but if you develop some exotic PDF with repetitive text-links, you’ll need to pay attention.
(p) ‘When a timed response is required, the user shall be alerted…’
PDF Translation: Doesn’t apply, unless the PDF contains JavaScript that utilizes timed response.
Wondering where to focus?
Here’s a simple guide to the regulation’s clauses in terms of the work they require in PDF remediation:
- (a), (c), (g), (h), (l), (n) — The bulk of the work
- (b), (k) — Infrequent or readily avoidable issue
- (d), (f), (m) — No problem, easily addressed
- (e), (i), (j), (0), (p) — Not applicable in PDF at all
