Historic scripts as MAYBE?

[Patrik Fältström]

On 28 apr 2008, at 08.55, Mark Davis wrote:

> So these are both referring to versions of IDNA data, not Unicode  
> data, and
> considering what would happen if we (in this committee, not Unicode)
> exceptionally allow characters to change status, AND it happens that  
> the
> IANA committee or whoever decides changes to the context/exception  
> tables
> adds MODIFIER LETTER RHOTIC HOOK to PVALID, removing it from  
> DISALLOWED.
>
> The rest of the message is trying to consider what the consequences  
> would
> be.
>
> Is it clearer now what I'm saying?

Yes, I was confused when you talked about 5.1 and 5.2 which to me  
reference Unicode versions.

> "Let's suppose that IDNA 2008 is issued based on Unicode 5.1"

IDNA2008 is not based on Unicode 5.1. It is defining an algorithm that  
is to be applied to any version of Unicode. The table is non- 
normative. So a codepoint that is assigned DISALLOWED will not move  
from DISALLOWED if not one of three things happens:

- UTC changes the data in the Unicode tables
- A codepoint is added to the exceptions table
- The algorithm is changed

You say the first is out. Good.

My personal view is that as we do not have MAYBE, things should  
_NEVER_ move from DISALLOWED or ALWAYS. Same reasons as always. Due to  
changes in ability for registration, requirement for sunrise, risk for  
applications to have the domain names no longer be accessible (or not  
able to access newly registered domain names) etc.

As it is now, my view is that the change that is "ok" is move from  
UNASSIGNED to one of the other categories.

But, of course changes like these can be made when the RFCs are  
updated. And when an RFC is updated, anything can happen.

    Patrik