the point of selective importing

[Walter Bright]

John Reimer wrote:
> And Walter, you particularly seem to be stirring this pot by repeatedly posting
> misinformation.  We have several times demonstrated the difference between the
> two systems.  If you don't understand what we are saying is different, please
> ask us to clarify rather than adamantly stating in every post that there is
> *nothing* different between the two.  The difference has been clearly
> demonstrated more than once.  You seem to be refusing to admit it.

So I've apparently missed something. Please explain what the semantic 
difference is.