Re: An analysis of mustUnderstand and related issues

I like this approach for adding message routing - its
very straight forward and simple.
Just wondering, if we go with this approach, what does it
mean if people don't use it?  Have we resolved the issue
of how do deal with targeted MU's that never hit the actor?
I'm worried by adding features (either as add-on's or
to the core spec) w/o changing the spec itself doesn't
help implementers resolve the issues they've run into.
-Dug