Paragraph by Paragraph: What Section 508 means for PDFs

The Section 508 regulations don't translate well to PDF - in fact, the regulations aren't very specific, clear or complete in the first place. Knowing how and when they apply to PDF, however, should give you a sense of what compliance costs in terms of time and focus. The tables below should help you understand this crucial point. Use of color coding is matched with descriptive text in the Table Key.

The Regulation Paragraph	Relevance to PDF Content
(a) "A text equivalent for every non-text element shall be provided (e.g., via "alt", "longdesc", or in element content)."	Must provide alternate text for every graphic image included in the PDF. Other descriptive text is also encouraged.
(b) "Equivalent alternatives for any multimedia presentation shall be synchronized with the presentation."	Not applicable for the vast majority of documents.
(c) "Web pages shall be designed so that all information conveyed with color is also available without color, for example from context or markup."	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.	Treat low-contrast text (shaded areas) as image [see paragraph (a)], or remove shading.
(e) "Redundant text links shall be provided for each active region of a server-side image map."	Not Applicable
(f) "Client-side image maps shall be provided instead of server-side image maps except where the regions cannot be defined with an available geometric shape."	Not Applicable
(g) Row and column headers shall be identified for data tables.	Must Comply
(h) Markup shall be used to associate data cells and header cells for data tables that have two or more logical levels of row or column headers.	Must Comply, although workarounds may be necessary for older screen-reader software.
(i) "Frames shall be titled with text that facilitates frame identification and navigation."	Not Applicable
(j) " Pages shall be designed to avoid causing the screen to flicker with a frequency greater than 2 Hz and lower than 55 Hz."	Not Applicable
(k) "A text-only page, with equivalent information or functionality, shall be provided to make a web site comply with the provisions of this part, when compliance cannot be accomplished in any other way. The content of the text-only page shall be updated whenever the primary page changes."	An "escape" clause of sorts, for pages that simply can't be made compliant any other way..
(l) "When pages utilize scripting languages to display content, or to create interface elements, the information provided by the script shall be identified with functional text that can be read by assistive technology."	Must comply.
(m) "When a web page requires that an applet, plug-in or other application be present on the client system to interpret page content, the page must provide a link to a plug-in or applet that complies with §1194.21(a) through (l)."	Pages containing links to PDF files must include a link to the Adobe Reader installer.
(n) "When electronic forms are designed to be completed on-line, the form shall allow people using assistive technology to access the information, field elements, and functionality required for completion and submission of the form, including all directions and cues."	Forms must be comprehensively tagged, with complete descriptions for each field.
(o) "A method shall be provided that permits users to skip repetitive navigation links."	Not Applicable
(p) "When a timed response is required, the user shall be alerted and given sufficient time to indicate more time is required."	Not Applicable

NOTE: The Section 508 Board interprets paragraphs (a) through (k) of this section as consistent with priority 1 Checkpoints of the Web Content Accessibility Guidelines 1.0 (WCAG 1.0) (May 5, 1999) published by the Web Accessibility Initiative of the World Wide Web Consortium. See this link for more details: