Exceptions (was: Re: sharp s (Eszett))

[Patrik Fältström]

On 8 mar 2008, at 21.29, Martin Duerst wrote:

> Given that the Unicode Consortium doesn't have any "IDN" property,
> the principles above very strongly suggest that we will have
> exceptions.

First of all, I agree with your principles.

I am not saying we should NOT have exceptions. I am saying that we  
should be aware of the fact we have decided to "grandfather" the  
decisions made by the Unicode Consortium, and then have exceptions.  
Where an exception is an exception. Something that has to be changed  
just because the rules used when creating what is grandfathered did  
not work 100% correct when applying to what we are doing.

But an exception is an exception, something not following the "normal  
rules". And we should be very careful with adding adding more.

Note: I am *NOT* reopening the discussion about MAYBE category here  
below. I am just trying to explain to people that might not have  
followed IDNA200x for so long time:

These exceptions, and need for such, was btw for _me_ one of the main  
reasons why we should have MAYBE. A category that is no longer with us  
due to consensus on this mailing list. From MAYBE one could "move" the  
codepoint to "PVALID" or "DISALLOWED" (according to the old ideas),  
for example when one find an exception is needed.

Without MAYBE, making changes after we are done with the documents  
will, hmm, not be fun.

The main reason why MAYBE is removed is because we had no really good  
idea on what should be in MAYBE. I.e. what parts of Unicode are we  
sure will be correct in the first version of IDNA200x?

    Patrik