From: http://www.tei-c.org.uk/Activities/SIG/Overlap/olm01.txt
See: http://www.tei-c.org.uk/Activities/SIG/Overlap/
See: http://xml.coverpages.org/hierarchies.html
     "Markup Languages and (Non-) Hierarchies."

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Overlapping Markup SIG

Fourteen in attendence.

We first discussed some of the problems involved with overlapping
markup. We agreed that the first thing we need to do is document the
problems of existing approaches, of which there are many (both
problems and approaches). Patrick Durusau volunteered to put together
a web page, to be placed within the TEI website, outlining various
existing solutions and briefly describe the general pros and cons to
each approach. We would then like to solicit comments on these
solutions from the TEI community in general, and ask community
members which of these approaches might address problems to specific
to their projects. This would give us an overview of the problems of
overlapping markup, and will also give us an indication if an
existing approach (or approaches) could be endorsed by TEI, or if we
need to find a new approach (or approaches) that will suit the needs
of the community. We hope that the work of the SIG will help to
inform the TEI's existing Stand-Off Markup working group.

In discussing the problems of overlapping markup, it was agreed that
the most commen problem is that of the markup of text (paragraphs,
sentences, chapters, words) vs. the markup of the physical object
(page, page or folio line, quire). It was agreed that a good approach
would be to begin trying to find a standardized approach to dealing
with the text/object conflicts, and that approach should be able to
be put towards other overlapping markup problems.

David Durand, member of the Stand-Off Markup Workgroup (which is
currently charged with issues of overlapping markup), has agreed to
create a listserv/email list for all those interested in overlapping
markup. The initial group will include all those in attendence at the
SIG.

David Durand explained the current approach TEI is taking to
overlapping markup, which involves separate XML files for each
hierarchy, using Xpointer and Xinclude to map between files. It was
agreed generally that this approach may be too dependent on heavy
encoding to be useful. It was agreed that it is important for the SOM
Workgroup to work closely with the TEI community, including those
present at the OMSIG, to make sure that approaches adopted by TEI
will be useful to the community.

The SIG has no recommendation on whether the TEI should have only one
or several 'official' approaches. It was agreed that it is still too
early, and this question should only be addressed after the TEI
community has had a chance to view and comment on existing
approaches.

It was agreed that any approach will need to be extensible in the
sense that any assigned elements (for example) would need to be
re-nameable for any project.