Use of MCE in OOXML

[MURATA Makoto]

Dear colleagues,

In my understanding, MCE was not used by Office 2007 and was
used to a certain extend by Office 2010, thanks to MS proprietary
extensions.  The next version of MS Office is expected to migrate to the
strict conformance class and heavily use MCE to record transitional
features.  I thus feel that poorly specified MCE will cause very
significant interoperability problems.  Jim and John, please let me
know if my understanding of MS Office is right.

Regards,

Makoto