Shirley Kaiser discusses accessibility and Adobe Acrobat on her site.
There is one element in Adobe Acrobat that does not meet the Government's 508 compliance, if this is the yard stick being used for accessibility. The area of non-compliance is complex tables. PDF tags only have TABLE, TR, TH, and TD tags available, which do not accept scope. Scope is what helps the complex tables become compliant in HTML. The only acceptable method for providing information in complex tables is HTML, at this point. One work around is to make the complex tables attachments or addendum and remove them from the original document (should the complex tables be provided in PDF format) and only supply them in HTML.
To keep it clear a complex table is one that has more than one set of header rows and often one of the header rows would span a selection of other rows. An example would be a table showing fiscal quarters of the year and the months that fall within these quarters, which would then show rows of related numbers. The top two rows create a complex header as each quarter header spans three rows and defines the months directly below them. Voice readers will capture these relationships quite well with the use of "scope tags" in HTML (this would look like <th scope="col"> for header tags and <td scope="row" in the first cell of the table's rows). Unfortunately, PDF does not have a corresponding tag.
I also pointed out that the more current Web browsers permit using CSS with printer designations that allow for a better representation of the information. This would help those people build one application, whether it be a Website or a PDF that prints in the desired manner and is accessible.
This may help keep yourself and your readers in the clear if 508 is their standard upon, which their accessibility work is being performed. Unfortunately there are no compliance standards, only guidelines. But, for most federal government organizations it is meet all of the targets to be compliant. 508 is a pass/fail hurdle.
Further information on 508 may be found at www.usability.gov/accessibility/index.html.
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