Q1 is mapping on lookup permanent or transitional?

[John C Klensin]

--On Monday, April 06, 2009 15:01 +0200 Alexander Mayrhofer
<alexander.mayrhofer at nic.at> wrote:

>...
> It should be required. If the user experience changes from one
> implementation to another implementation, users will be
> confused, disturbed, and will complain.

Of course, user experience changes regularly, both between
implementations and between versions of the same implementation.
Users get confused and disturbed.  Then they complain.  And then
they adapt.

And, if any of 
    Mac System 9.x -> Mac System X
    Windows 3.1 -> Windows 95
    Windows XP -> Windows Vista
    MS Office 2003 and earlier -> MS Office 2007
    Internet Explorer 6 -> Internet Explorer 7

can be used as examples (and I have many more, but they would
probably be less familiar), they adapt a whole lot faster than
"forever".   What we need is a plausible reason for making the
change other than "we did this to irritate you".  The users
don't necessarily have to believe that reason, but it has to be
plausible.

      john