Michael, here is more on my concerns about the foreign-element handling in
ODF 1.x and needing the fall-back to be predictable by producers who want to
be careful that consumers will achieve a reasonable result:
1. The substitution process is incompletely-specified. I.e., if a foreign
element has namespace bindings and use of XML-defined attributes (xml:lang,
xml:space, xml:id, RDFa attributes, etc.), those need to be absorbed somehow
if the tags are simply dropped and the body retained as part of the text.
(I was thinking that a substitution with