XPS and OPC

[MURATA Makoto]

Dear colleagues,

Happy New Year!
While reading the Ecma XPS specification, I find the following sentence.
    The OpenXPS Document format extends package-level interleaving and
digital signatures as    described in the OPC Standard.
Does this statement might mean that conformant XPS documents cannot
behandled by conformant OPC engines?  I had a quick look at XPS.
Itappears that XPS does introduce some additional requirements and
evensyntactical constructs.  I am wondering if some of them
shouldactually be moved to OPC.  For example, the content of
17.1.5(Interleaving Optimizations and Digital Signatures) in XPS does
applyto OPC in general.
When we send a liaison statement, we should ask whether OPC should
beextended for better support of XPS and also ask what the above
quotedsentence mean.
-- 
Regards,

Makoto