I am new here, and still learning TEI and the "%" extensions, including
"facs" are important to my project. I agree with Dot that the facs tagset is
lacking, just a little. Whilst I think the overlapping zones approach is
fine, and the balance between simplicity and power is ok, and I can live
with rectangles, I would very much like to see a simple way of indicating to
a processing engine that the orientation of the text in a zone is not left
to right, but top to bottom, or bottom to top. For any facsimilie driven
data capture process, this capability is useful. 

To give some idea of the document set I am working with, see this crude mock
up using the Image Markup tool:

  http://zensorac.info/xml/workshop/demo1/test1.htm

These are 18th century administrative documents, Tasmanian convict records.
Though this example doesn't show it, it is *very* common for text to be
written vertically, all over the normal text. 

As you can see, these are highly structured documents, raising issues
somewhat similar to Paul Caton's abstract for TEI2008 which talks about
newspapers (ie. where the physical layout really matters):

http://www.cch.kcl.ac.uk/cocoon/tei2008/programme/abstracts/abstract-110.html

I am too green at all this to offer any further concrete suggestions, but
look forward to interesting discussions with those of you who are attending
TEI2008. I would be pretty happy for now if there were a way to indicate
text orientation, as mentioned above. Just an attribute on the zone perhaps?

Cheers to all,
Sandra