Touchstones for "Mapping"

Harald Alvestrand harald at
Wed Mar 25 21:08:36 CET 2009

Andrew Sullivan wrote:
> On Tue, Mar 24, 2009 at 03:46:01PM -0700, Lisa Dusseault wrote:
>> 1.  Canonical forms:  encourage labels to be stored and displayed,  
>> whenever possible, in a canonical form.  The protocol only uses the  
>> canonical form.
> Is that "labels" or "U-Labels"?  (I was going to ask this clarifying
> question at the mic, but we were running out of time).  My own opinion
> is that much of the time, if you have to store something, it would be
> better to store the A-Label, becuase then you can be sure you could
> actually resolve the same owner name if you had to do it again.  The
> symmetry in IDNA2008 is a help in this case: it lets you do that and
> get back "what the user typed".
terminology quibble:
if it's an U-label, then it's already in canonical form....

the term "M-label" has been tossed around as a term for the label that 
isn't an U-label, but can be turned into one by applying the standard 
mapping operation, to separate that from other Non-ASCII labels, but 
isn't in the documents at this moment (see -defs-08 section


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