logical structiure and behavior in Accessbility tagged PDF

Start with well formed FM files. Begin with the default for tags in the PDF setup and tweak to fit your documents' needs.
Look closely at the tagged output PDF(s) structure tree, read order, etc. to better understand what the output from the FM files/books is.
You will have to do some post-processing with Acrobat Pro. You *must* have at least release 8 (updated to 8.1.3) or better.
This gets you the table inspector & tables can be a "deal breaker".Perhaps a post at this thread will help.
[url]http://www.acrobatusers.com/forums/aucbb/viewtopic.php?id=15622[/url]
It is a starting point.
Obtain the current information for Acrobat 9 as well.
Review the PDF Reference(s) & the addendum material Adobe has provided to the ISO 34000 standard (aka PDF version(s)).
Additional information may be found in the SDK documentation associated with the different PDF versions.

Some tips:
Take the time to understand the check points provided by W3C.
Be attentive to tables in particular.
A lady once told me FM is "wonky" with tables. She's right. imo, nothing better.
Post processing tables in PDF with Acrobat Professional is interesting but not a productive use of time.
Look over the differences between alternate and actual text for figures.
Assure you have good, normative templates. No overrides, untagged formats.
Assure you tables are in fact "tables" and not something used to provide "quick 'n easy" layout.
Assure your "real" tables do make use of creating the header row/cells at table insertion.
Whoever is actually going to work the FM & PDF files is going to need a chunk of time to actually study the information, work what curriculum is available and practice-practice.Get the file "AdobeAccess7book.pdf".
If you come across how to get the CD that this file was on I'd sure appreciate knowing that.
The CD has the practice files used by this tutorial.

If you can, share what you learn here; speaking for myself, FM to PDF for S508 accessible PDFs is a topic I'm rather keen on.

Be well...

Hi there sfturner,
Curious here, where are your S508 PDFs going?

In your post you wondered about logical structure and associated levels.
Let the PDF reflect, to the greatest extent possible, the hierarchial structure found in your FM files.

Lynn Price (Text Structure Consulting, Inc.) has a tutorial for FramMaker (Editing Structured Documents)
In lesson's book file, the following paragraph tags are found in the book's FM files.
AppendixNumber
Body
CellBody
CellHeading
ChapterNumber
Equation
figure
figure_text
Heading1
Heading2
HeadingRunIn
Item
Mapping Table Cell
Mapping Table Title
Paragraph
Paragraph1
subtitle
TableFootnote
TableTitle
Title

One way to stage the hierarchy of the tagged output PDF would be something like this:
ChapterNumber
.Title
..Heading1
...Heading2
....Of course, one can further refine below level 5 in the tag hierarchy.
The point is that, if the proper authoring application is used, one can, to a great extent, pre-stage the hierarchy
of the output PDF tag hierarchy. Keep in mind that the "input" is mapped to the tag elements provided by Acrobat.
To accommodate a range of input agents, the mapping is (by design) not exceedingly rigid.
With FrameMaker you have the first of the preferred authoring application for tagged output PDFs.
From long meanders in Adobe's web space my take on the order of precedence for authoring applications that actively support tagged output PDFs is -
FrameMaker > InDesign > PageMaker > MS WordSo, you establish the logical hierarchy in FrameMaker. Then you look at the output PDF. Note that you will often need to adjust read order with Acrobat Professional (8.1.3 or newer). Browse the pages and the Tag Structure.
Not what is need? Missed something?
Return to FrameMaker to correct the issue. Clean, well-formed templates are the goal. Once these are in hand you work within the template. This provides tagged output PDF(s) that are in "center court"; however, do accept that there will always be some post-processing required. This will be time intensive.
Keep in mind that you absolutely want to pre-stage as much as possible in FM and minimize post-processing with Acrobat.
You can loose a week of work in a blink of an eye (even when you have something of a clue about what you are doing).
There is no "undo" when editing the Tag Structure. Which is to say you get it right the first time, every time or end up flushing it and starting again. The success path often requires a change in what you've consider to be "rightous FM workflow techniques".

With that said, you still have to support the day-to-day production deliverables. You need your production set of FM files available for that. You may have to produce a snap shot copy of all & work on that to get the FM & resultant output PDF files where they must be for S508 accessibility.
Once accomplished, these "new" files would call for updating to reflect incorporated changes to the day-to-day production files.

Other tasks to consider.
Figures - often, these are incorporated by reference into the FM file. But, are *all* parked inside an anchored frame?
The anchored frame affords you the opportunity to pre-stage the PDFs' Figure tag element Alternate or Actual text.
Not using this will mandate that each individual Figure element in the output PDFs must have the element's Alternate Text entered manually.
Every time a new PDF is produced the manual input will have to be done again.

Some more observations:

Enclosing text flow in a single column table with the table borders & row/column lines set to none.
This results in a layout table. An undesired thing when output PDF is to be S508 accessible.

Remember, any table inserted in FM will be tagged with the table element in the output PDF.
PDF table elements will have to comply with S508, 1194.22 (g) & (h) for the PDF to be S508 accessible."Insider" abbreviations. Use -
-| foot/feet not " ' ", inch/inches not " " ", Elevation not El.
-| The "dash" character can be more than a little awkward when read by a screen reader.
You can get "something minus something" or "something TO something"; depends on context.
Consider replacing the dash character when used in autonumbering schemes with an en space
(standard character set, ANSI No. 0150).

-| Symbols - Locate the "FrameMaker Character Sets (Windows)" PDF. It was installed when FM was installed.
Make a close study of it. Section 508 PDFs must have correct mapping to Unicode for the characters in the PDF.
Example - Is every occurance of "degree" from the Symbol character set (ANSI No. 0176) or the "ring" character from the Standard character set (also ANSI No. 0176)?
Confirm that no characters are using reserved values.

filename = Character_Sets.pdf

FM6 -> C:\Program Files\Adobe\FrameMaker6.0\OnlineManuals
FM7 -> C:\Program Files\Adobe\FrameMaker7.1\OnlineManuals
FM7 -> C:\Program Files\Adobe\FrameMaker7.2\OnlineManuals
FM8 -> C:\Program Files\Adobe\FrameMaker8\Documentsn.b., Some of the graphics shown for the Symbol set in the FM7 document are incorrect.
I've not done a cross-check against what is in the FM8 document.
Also, remember character set support/implementation has some differences between FM7 and FM8.

-| Language - I've some FM files that started in FM6. Sometimes, some do not pass through that the language is
English-US (no idea why - have not researched this yet). Otherwise, FM 7.1 | 7.2 | 8 are reliable for passing this through and it (language) is parked under the parent element of the PDF.
However, the value for Language, under the Advanced tab in the Document Properties will not reflect this.
Do note that the Full Accessiblity Checker does "see" it.
I've found it is worthwhile to run a Preflight Fix-up via a Batch Sequence to assure the language is set to English-US for all PDFs that are to be Section 508 accessible. Note: Acrobat 8 Professional/3D or newer is required.

-| Bullets - Be sure that the graphic used uses a value (ANSI/HEX) that maps to Unicode.

-| Generate files - May observe that 2nd, 3rd, subsequent pages have one or two text lines that fail to be tagged.

-| Publish trial output PDFs frequently as you develop your FM Books/files. Review each page with the TUOR tool.
This will locate the paragraph tags you thought you had but missed. Fix this back in FM.

-| Do use Save As to Text (Accessible) (*.txt) for each tagged output PDF to QC read order.

Be well...