Intro to PDF/Universal Accessibility

What do you get when you pull together a gathering of end users with disabilities, frustrated industry folks who spend a lot of time cleaning up PDFs for customers so that their documents are accessible, and IT professionals who focus on accessibility at various software companies? 
A standard for accessible PDFs. 
There hasn’t been a lot written about the PDF/Universal Accessibility standard (aka PDF/UA, or ISO 14289), so you might be under the impression that it’s a fairly new endeavor.  It’s not.  It’s been a work in progress for more than five years, under the auspices of AIIM where several other PDF standards are nurtured.  There have been committee reorgs, dramatic leave-takings, and lots and lots and lots of hard work. 
So what does accessibility look like in PDF?  The PDF language contains a number of constructs for the structure of any given document.  Accessibility for PDFs must then give access to these constructs in such a way that any given assistive technology, such as a screen reader or magnifier, can easily expose every element in a given document to an AT device.  There must also exist a way to edit the constructs in the event that any given authoring tool isn’t pristine in writing out the constructs.  There are three basic ways that you can build accessibility into your PDF documents; all are need to build fully accessibility documents. 
First, you need to have the document structure identify all parts of the document correctly. It sounds simple, but it isn’t really.  It’s quite possible, for instance, to have a header or footer in a document that isn’t marked as an artifact when saved as PDF.  You haven’t created invalid PDF if you’ve done this from your writer, but you have created a challenge for an accessibility tool – marking